"Governor Wells? We are the Personalia, and we have some tests we would like to run on your planet. They arise from an idea presented to us by Governor Kempe of Rehome colony."

John Wells was surprised. Normally Bob Kempe, as the Governor of the human colony on Rehome, would phone John personally. After all, John had been Bob's Head of Administration before taking on the Governorship of the New Eden colony planet. He did not say anything about that.

"Really? What kind of tests, and where do you propose to run them?"

"The tests would all be done in the lands outside the crater that your colony stands in. The idea is to discover whether we can scare away the mega fauna – the giant animals and their predators out there. Governor Kempe had discovered that very large sea creatures could be scared off from the fishing areas close to shore, using a mechanism left by the Braalians. The mechanism was attached to the ocean heat pumps; and it used sound vibrations to chase off these creatures. Governor Kempe wondered, could a similar sound frequency technique perform a similar task with your problem creatures on New Eden."

John responded positively. "That sounds an interesting proposition."

"Thank you. We intend to place several sound emitters on the ground surface and observe the reactions of the animals to each sound. We intend to try a wide range of frequencies, quite loudly, to ascertain the effectiveness of each frequency, and adjust the sound levels of the effective ones until we discover the most efficient solution."

"That seems a feasible scenario. What happens when you find a suitable frequency?"

"Simple. We establish a boundary with the sound emitters overlapping, and that clears an area where your settlers can log and start farming."

"Great idea. I am not so sure the settlers will want to move out there, though."

"What? Why would they not take advantage of pristine forest and grassland?"

"Human perceptions, I am afraid. Humans tend to distrust a barrier that they cannot see. It is a daft reaction, I know; you don't have to tell me, but it is a fact. People are wary of such invisible boundaries between them and dangerous wild animals."

The Personalia voice was astounded. "This is a weird reaction you postulate, Governor. Just because an effective barrier is not made of solid matter, they distrust it?"

"Yes. There is an unconscious fear that the invisible barrier might fail; and if it failed, they would be under threat without realising it. It is the fear of the unknown that unsettles them."

"This must have something to do with your evolutionary history, that you only trust solid walls to protect you."

"It was not so much only a wall. It was the barrier that had evidence of its danger. Many boundaries between nations that distrusted each other had an example. It was a pair of tall fences, with land mines planted and hidden in the space between the fences. That was very effective, even though one could not see the mines. People knew the mines were there: an animal would set one off from time to time. It was the confidence in such minefields that counted. Such confidence is simply not present for a sound frequency barrier such as you propose."

The Personalia mulled over this point. "So, a barrier has to be either visible, or be regarded as visible; believed to be dangerous, or preventing danger, to be felt to be effective."

"Yes. Something that can be switched off without any indication of that state, is not regarded as acceptable, but if it has a visible component that allows you to be immediately aware that it is missing: that is fine, as far as it goes. A passive barrier like a wall or stout fence, or an electrified fence, is still preferable."

"How about a simpler, less expensive, fence that is backed up by the sound generators?"

"That might be acceptable. We then have to consider other factors that do not exist within the crater walls. First of all, smaller animals that may use burrows. We have found burrows within the crater, but none of the animals has survived here, so we know nothing about them: they may be poisonous, or have sharp claws, or carry unwanted diseases, and so on. They may exist outside the crater perimeter mountains."

"But with an external fenced off area, you would have additional advantages; such as access to timber for all your wood needs; access to extra farming land, space to expand your accommodation needs, and so on."

"That is so, but there may be bacteria present in the soil that are inimical to human life. We would have to test for that: send soil samples to be analysed at the nearest agricultural laboratory. That would mean one on Earth. So even once we had some sort of barrier in place, it would take time before we could risk any settlers. Even then, we might have to offer a bounty to the first settlers, to encourage them to go."

The Personalia voice declared, "We could probably do your soil analysis for you. We can set up a lab within one of the ships in orbit, and bring all the chemicals and glassware from Earth. In fact, we might have to set up our own satellite for this purpose, for our Base ships do not have enough free space that we could devote to a laboratory unit. There are bound to be other items that have to be tested. That could be a fun project, too, as we love discovering new things."

John was suddenly looking at the project with new eyes. "If you were to set up such a research satellite round New Eden, we certainly could give you more items to analyse. Soil analysis to determine how fertile the soil is for particular crops would be a useful tool for us. Again, if brewing and distilling get started on this planet, it would be very helpful to be able to analyse their products before they go on sale, just to check how strong in alcohol the brew is; or the spirit that they distil."

"That should not be a problem. It is a simpler set of tests than for soil analysis. Every soil sample is likely to be unique, and there would a be a range of aspects to be checked for; such as PH, trace elements, fertiliser components, humus level, etcetera."

John was anxious to proceed with the proposed sound frequency tests. "Can I have a say in what area you use for your initial sound tests?"

"Certainly. Did you have a particular location in mind?"

"I do. The only break in the crater wall is where the waterfall descends. That is where we also have the outfall for our sewage pipe. If we clear an area out there, we could build a sewage treatment plant there. The sewage outfall means that when it falls into a pool it will be aerated, and that is a first treatment. If the pool then descends into a marshland with rushes and other plants, the plants will also clean and clear the water, such that it can be allowed back into the freshwater stream that descends from the crater. That will give us an environmental solution; much better than a stream of sewage as we have at the moment."

"A good idea, Governor. We approve of your concern for the environment. We shall do our tests a kilometre downstream, wherever we find suitable sites for the sound emitters. It may take anything from a day or two to several weeks, to establish the best frequencies, sound levels, and so on. We shall keep you informed. Please warn your people of what is happening, in case they should observe Landerships going down to land outside the crater mountains. They might imagine it was an accidental crash happening."

John retold all this to Muriel and Gloria that evening, as he relaxed in his favourite chair with a glass of imported wine in his hand. Gloria was sitting on his lap, wide-eyed at the amazing plans of the Personalia. Her mother Muriel was seated on another comfy chair, cuddling a sleeping baby in each arm.

"Will anyone be willing to go out there, to test the sound barrier they will set up? It sounds terribly dangerous," Gloria queried. Muriel just smiled, not saying anything. She was happy holding her and Gloria's babies which were much the same age. Both she and Gloria were married to John, and happy enough to be so. A year previously, Muriel had engineered matters to get John to marry her as well as Gloria. Muriel's abusive first husband had been shipped back to Earth from Rehome colony, allowing Muriel to divorce him. She had then taken advantage of the marriage laws on Rehome. She deliberately seduced a drunken John before he had taken Gloria's virginity, and got him to promise to marry them both if the law allowed it. She had already checked that it did, but it came as a surprise to John. Once Gloria realised John had bedded both of them, she accepted that her mother and herself should share John as their husband.

However, sharing John brought out the competitive streak in Gloria. Instead of continuing with her budding career in the medical centre administration, she did not want her mother to outdo her by having a baby first. Once Muriel declared that she had decided to try for a baby while she was still young and healthy enough, Gloria opted to become pregnant herself, and they embarked on that joint project with John's enthusiastic cooperation.

Now, with both having successfully given birth, they were more at ease with each other. John was happy to appreciate both women, and they now enjoyed the status of being spouses of the man who had become Governor of New Eden colony. They were both treated with due respect by the settlers and the colony staff, though one was much older and the other much younger than him.

John assured Gloria that volunteers for the tasks beyond the mountains would be forthcoming, as the men would be offered a bonus for working outside the crater. He laid down his glass on the small table next to him, as he gestured with his hands to make his point. "One can always find men able and willing to take risks. In this case, the Personalia will make pretty damn certain there would be no actual risks; but it will take time for the ordinary settler to accept this. It might sound expensive, to pay high bonuses for non-existent risk-taking, but it is cheap in the long run. As soon as we have established a track record of safe operation, other settlers will be happy to move there, and we can drop the bonuses entirely. We replace them with crop guarantees for the first year. That will attract settlers to have a go."

Not consciously thinking about it, has hands slipped under Gloria's clothes and he fondled her large breasts. Gloria sniggered as she enjoyed the cuddle. "John – not in front of Mum!"

"Hmmm?" He suddenly became aware of his actions. "Oh, yes. Certainly in front of your mum. My wonderful, darling Gloria, it is a year since you both married me, and you still feel uneasy in front of Muriel. You really have to stop thinking of Muriel as your Mum. You are both my wives, and the mothers of my sons, so you must think of Muriel as simply your co-wife. It makes things so much simpler. If you continue to think as you have been doing, my two sons are not just siblings, they are uncle and nephew, your son is Muriel's grandson, and Muriel's son is your half-brother. These are complications we don't need, so please just accept Muriel as my other wife. As for Muriel watching me paw your breasts, I'll have a go at her breasts later, once the babies are in their cots, won't I, darling?" He smiled across at his other wife. "I know you like to have yours fondled too, Muriel. The children have first call on these beauties at the moment, so I'll take my chances when I get them, and even sup some of your surplus milk. I never expected to like breast milk, and you each have slightly differently tasting milk. Surprising, but fun."

Muriel had also been listening to what John had said earlier, and now spoke up. "John, my darling, if it is a matter of a physical barrier to make people feel more secure, why not put up a wire netting fence between strong metal posts? It would not stand up to a really fierce assault, but the sound emissions should stop them coming even close to it, shouldn't they?"

"Good idea, Muriel. It would be a physical barrier, but a lot cheaper than a wall or any other solid barrier. Wire mesh would be much cheaper. I don't know about the posts, though. These could be expensive."

Muriel had thought it through. "Well, you recall all your talk about the railway line on Rehome? If you could get hold of sections of worn-out railway track, that would be much cheaper than new metal posts, wouldn't it? I can imagine the Landerships dropping sections of rail vertically from a couple of hundred feet up, and they would be driven straight into the ground. It is like a knitting machine, to my mind. Then you weld the wire mesh to the rails. Can we do welding yet?"

"Yes, I do believe so. Battery-powered welding machines are available nowadays, and with the new alien batteries, they have more power to do the job. We certainly can import such machines. I have some doubts about the metal pins from above concept, though. If that part of the intended line was rocky, the rail pins might bounce off, and if it was very boggy, the pins might vanish entirely. The general concept is fine, Muriel. It just would need advance planning of the fence line, to ensure all the rail pins would go in as intended. The odd rock could be avoided, but a larger rocky surface would be problematical. Sheer cliffs are fine – they could be incorporated as part of the barrier, but level rocky surfaces would either have to be bypassed to one side or the other, or you build a concrete wall across it, of sufficient height to make it unclimbable."

Muriel nodded sagely, happy that her suggestion was being accorded proper attention. John's genuine consideration of the views of both Muriel and Gloria was part of the reason they loved him. His life as the Governor was always very busy, as the small colony kept expanding. Every expansion meant more additions to the social requirements of the community: school, medical centre (and now a hospital), community hall for everything from parties to concerts, a music centre where young people were taught to play instruments, police station and jail; a town hall in the planning for social events and public meetings.

The colonial offices were a mix of financial control, legal organisation, administrative structure, and immigration department. The staff, many of whom had come from Rehome where they had learned their trade, were a great bunch; always willing to help out as needed.

With the arrival of a number of retail shops, the staff had branched out into the aspects of business that involved tax and business standards. The school had now to place more emphasis on arithmetic, so that the future local community could properly calculate their purchases and people not be overcharged for goods. Geography lessons were of New Eden geography, and a basic understanding of how the worlds of Earth and Rehome worked. While Rehome was similar to New Eden, Earth was going to seem like a foreign land to children born or brought up on New Eden. The local schoolchildren were all youngsters whose parents had brought them from Earth or Rehome, but some were young enough that New Eden was the only planet they were aware of, in their short lives.

It took little more than a couple of days for the Personalia to provide and install the sound emitters in a wide arc of a half kilometre radius from the waterfall. Unfortunately, this piece of land was still well up the side of the mountain, and there were no giant beasts anywhere close. The nearest creature was a flying reptile similar to a pterodactyl, but it was no different from the ones that were found inside the crater, and so were not an unexpected threat.

This minor disappointment spurred the Personalia to choose a new location further down and into a wide valley where large beasts had definitely been seen. The sound emitters were placed in a circle next to the river, again using a half-kilometre radius to be able to measure the results accurately.

Several more days passed before John heard from the Personalia. "Governor Wells, we have now established that there is a sound frequency that makes the animals turn away and leave. In fact, there are two frequencies: one affects the predator species, the other affects the grazing species. We have adjusted the emitters, so that they send out signals on both frequencies at the same time. We have observed the results of these frequencies, and the effect is quite satisfactory."

John was naturally pleased. "Excellent. I have a question, though. How can any of our settlers get to your fenced-off area?"

"Ah. That is a difficulty. We could fly them there, but that is not a long-term solution. You also have the problem of getting over the mountains to access the land out there; or perhaps through the mountain ... leave the question with us for now. We love solving problems."

John thought he should brief the local community on the plans for future life outside the crater. It was a concept the colony had not considered before. He called a "town meeting" at the community hall, which substituted for the future town hall, on the subject of Future Expansion of the Colony, and a large turnout greeted him as he took to the stage.

"Fellow colonists," he started. "I have called this meeting as I have been given options I never expected to be considering at this early stage. Our little colony has been growing steadily, and shows every sign of being a healthy community for many years to come. I have to thank you all for that happy state of affairs.

However, as much of the land in this crater is needed for growing food crops, there is a limit to how many people we can accommodate within the crater space. This means we have a few options. One is to reduce the space for growing food, while expanding the land area of our township. That leads to a food shortage before very long. Another option is the reverse: restrict building houses, etc. to maintain a good farming community. Again, that leads to difficulties, as families get larger and our children start looking for houses when they leave home and get married.

You will note that these difficulties are caused by us being stuck within the crater walls. Our friends the Personalia – the intelligent spaceships – took up a challenge suggested to them by the Governor of Rehome. On that planet, giant sea creatures threatened the coastal fishing industry. It was discovered that the former owners of the planet, the Braalians, had installed a mechanism in the ocean shallows that used sound frequencies to deter the sea monsters; so the mechanism was switched on. That solved the problem. Governor Kempe suggested that a similar mechanism might work with land monsters.

The Personalia phoned me to ask permission to test out this idea, and they have now found frequencies that deter both the giant grazing animals and the giant predators. The Personalia tested this out in a circular area beside the stream that starts as the overflow from this crater. They say it works satisfactorily, but I pointed out that the area they have cleared by this method is a considerable distance on the other side of the mountains, so how would any settlers expect to get there?"

"They accepted this as a problem, and are looking into it, but any sensible suggestions from yourselves would be welcome. At this point, I am open to questions." John halted and looked around, expectantly. For a moment or two, there was silence, then a man spoke up.

"Governor, do you seriously suggest that we go out among these monsters, only protected by some sound projector? What if it fails? How do we cope then? And how would we know if it failed?"

John peered into the crowd, to see them man better. He recognised him as an inveterate moaner, but John knew not to point this out. "Pablo, isn't it? Pablo Hernandez?" The man nodded, accepting the recognition.

"Pablo, thank you for your keen and perceptive interest. These very points have been discussed, and we recognise that they are valid questions. We certainly need some noticeable method of being aware that the sound emitters are still working. One can have a visual signal, such as a flashing light, or an audible one, such as a loud beep every few seconds. As long as these signals continue, you would know things were fine. We still are faced with: what do you do if the signal vanishes? In the short term, settlers could be provided with the equivalent of the old Elephant gun: some firepower to bring down any intruding animal.

However, we have thought ahead, to when we can have a much large area to settle. Once all the animals are cleared from that area, we envisage a physical barrier, probably with tall metal fence posts stuck in the ground – perhaps using old railway track lines – with strong wire mesh welded between the metal posts. That sort of barrier would be electrically charged, just like the old electrified fences for cattle. It would of course take time to install such a fence; and as it would be many miles in length, it will take time to get it up and running as a complete fence. Does that answer your reservations, Pablo?"

Pablo seemed stunned that his moans were so easily answered. "Yes, sort of. I am still not happy about this sound system of deterrence."

John replied, "Neither am I, Pablo, but the Personalia say it works, and they are expert at what they do. We just have to take this one step at a time, and we might get better solutions in the interim. You do accept that we have to get out there at some point?"

Pablo was forced to agree. "Yeah, I see that, Governor. I hope we do better than this."

Another man added another query. "Governor, how the heck do you expect we can get from inside the crater to land on the outside? I don't intend climbing the mountains, for a start!"

"Another excellent question, sir. It is one that I myself put to the Personalia. They have promised to come back to me with an answer. I have no intention of moving into that area without having a solution to the access problem. It is a fact that the Crater Mountains prevent the giant creatures getting to us; but the same fact operates in reverse. The mountains prevent us from getting to the site. We will not make any move until that question is resolved, I assure you.

Can I conclude by saying that this discussion is about a situation that may take a long time to become practical. I just wanted it to be put before you, so that everyone will have time to assimilate it. You may wish to offer considered advice to those who have to progress it. Can I thank everyone for coming, and I look forward to hearing your suggestions once you have thought it over? All suggestions to the Admin department, please."

It took a week before the Personalia reported back to John Wells with their solution. They had already started on building a nuclear powered tunnelling machine to bore through the mountain, with a number of their own mechanoids deputed to the task of removing the shattered rock that was excavated, using small dumpers on rails laid on the floor. This machine would mostly use sound projectors to shatter rock in front of it, starting from the outside of the mountains, tunnelling towards the crater on a gentle incline upwards towards the crater. The tunnel diameter was planned to be flat-bottomed but with a curved top, and wide enough for a single cart to go through in one direction. At the middle, and the top of the tunnel, a thick wooden door could be closed to seal the tunnel, with a long metal bar to act as a bolt socketed into the side wall. This was more to make apprehensive humans satisfied of their security than it was to achieve anything in particular. A sound frequency transmitter could be installed next to the bottom entrance, to deter any animal that happened to find itself at this point.

John thanked the Personalia for their work, and asked how long the tunnelling machine would take to reach the upper end. The answer was indeterminate, due to lack of knowledge of the rock structure inside the mountain, but anything up to several years was anticipated. If the Governor was happy with the idea, perhaps a second machine could be built and start digging from the top end of the tunnel?

John was delighted at the suggestion. "This would cut the tunnelling time nearly in half!" he exclaimed. "Please go for it. I will get some rules set out, so that no one will come near while you are working at this end. That should prevent industrial accidents. We should also work on a road from the tunnel to the fenced-off area that you are clearing of animals. I can't put men onto that task, so perhaps you can come up with a road-building machine?"

The Personalia agree that his suggestion was sensible, and added to it that a clearance on either side was needed; partly for protection of travellers, but also for the movement of machines and materials while the road was being constructed. The road could be built while the tunnel was being constructed, the Personalia averred.

John had something else to say. "It has been suggested that a metal fence could be installed to act as a boundary for a very wide area that had been cleared of large animals. The idea was to use redundant sections of rail line, dropping them in a vertical position from height, so that they sank into the ground sufficient to make them rigid. They would be placed at say 5-metre intervals, then one would weld strong wire netting to these upright posts. Finally the structure would electrified, so as to give an electric shock to any animal touching it."

"That sounds a fairly practical method of placing a boundary barrier in place. We shall look into it. We suspect that it would require a very large number of rails, if the barrier is hundreds of kilometres long."

John asked them to provide a digital map of the landscape outside the crater, in the direction of the proposed area to be cleared of giant animals. The Personalia were happy to oblige, as this would show what they had achieved to date, and where the new fence might be run. John was then able to work out a plan for his settlers to use once the tunnel and road were available. This would be many months ahead, so he had time to get people used to the idea. Going beyond the Crater Mountains was still a scary idea to comprehend, and the prospects for farming in the new location were more risky than in the crater.

John recognised that his intention of a bonus of some kind would indeed be essential. It was not the actual risk factors that determined this, it was the human apprehension that such an adventure engendered. He phoned Bob Kempe, Governor of Rehome; his former boss.

"Bob, The Personalia have proved that certain sound frequencies scare off our giant animals, so we can set up a barrier using these frequencies. We know people are not going to be totally convinced that it works. In fact, they are concerned that if it failed, there would be no way of knowing that."

"John, it sounds like situation normal. You can point out facts until you are blue in the face, but until folks have some reason to believe they are safe, they are going to be extra cautious."

"Yes, I was aware of that, so we are using a belt and braces arrangement. The sound emitters need to be fitted with a visual or aural indication that they are still working, but even that may not be enough. Muriel suggested a fence of metal poles and thick wire netting – with the poles being sections of old railway line dropped from Landerships. The Personalia are looking into the feasibility of that concept, but I am hopeful, provided it is electrified."

"That is sounding more like it, John. Where does your fence line go? Will it fence off enough land?"

"It should do. That kind of fence can be taken up and reused further out as time goes on. The wire mesh should be readily replaceable, provided it does not rust. The test area for the sound emitters is a bit away from the mountains, so there was the question of getting to it. I have the Personalia building a tunnel through the mountain chain, and a road from the tunnel to the fenced-off area to be our test site. What I want to ask you is: How do I motivate settlers to have a go at this new piece of land? My own thought was a bonus of some kind, but how much? Any thoughts?"

Bob thought for a bit, making minor noises to let John know he was still there, thinking. "John - Do you have any settlers who keen to practice shooting, or may be idealistic game hunters? What I have in mind is a sort of guard detail, who can patrol the barrier area, and if necessary, shoot any large beast that approaches. You may have some men in your defence force that could do this, but it would be best to have civilian volunteers who would jump at the chance of a shot at big game!"

John brightened. "Hey, that's a great idea! We are bound to have a few like that among our settlers. They just won't have guns, as they weren't allowed to have such weapons with them when they arrived. We can supply suitable guns, and make sure the guards are properly trained in safe gun use."

"Yes, that is fine. John, I hate to mention this, but there is another factor that you have ignored. As you are the Governor of this colony, the people expect you to lead them; and as you are going to say it is safe to go out beyond the mountains, guess who has to be out front, leading them?"