It was a letter that upended my world. Not one of the “Dear John” variety; that would have been less painful. Nor was it a “We Regret To Inform,” but the sense of loss, while not as acute, was even more all-encompassing.

No, it wasn’t a letter of the paper-and-ink kind at all. Instead, it was one of the many small sigils that make up those and many other missives, the second of the twenty-six characters that comprise the English alphabet.

The letter that irrevocably changed my life was a simple “B” where it did not belong: in a small field on a medical chart, the one that denoted the blood type of my fifteen year old son, Travis. His mother’s blood type was “O.” Mine is “A.” High school biology was a long time ago, but I recalled enough to quietly ask the nurse in the emergency room whether I had remembered correctly. The pained look on her face told me that I had even before her words confirmed it.

Something so small, and yet it made me question everything.

What had brought Travis to the emergency room was a typical childhood accident: a skateboard trick gone wrong. Even as they were putting the cast on his arm, he was laughing and talking about how “epic” it would have been if he had landed the stunt. I just chuckled and advised him to be more careful, tousling his hair. I was proud of his bravery and athleticism, even if I didn’t always understand its impetus.

That was our relationship in a nutshell. I loved him, and he loved me, I knew. But we were so different from each other. Not physically; until that errant character I barely glimpsed on the nurse’s screen, I would never have doubted he was my biological son. He was tall like me, filling out into a stocky young man like I’d been. I had thought his dark brown eyes and hair were inherited from me, as well. But they weren’t mine; they were my doppelgänger’s. They were the features of the cuckoo that had left its egg in my nest.

I always thought that our differences, psychological and emotional, were due to his mother’s influence. Allison had been impulsive– even impetuous– when we were younger. Our meeting in college had gone almost exactly against the planned events of the day. Her older brother, Jake, had introduced her to my older brother, Evan. They were best friends, both of them on the football team of our small college. Both juniors. Both star players with a chance at the big time after graduation.

Allison was a beautiful, delicate-featured, blonde and blue-eyed freshman that Jake was sure would be perfectly matched with Evan. She threw a monkeywrench into her brother’s plans when she instead took to me, the studious and introverted younger brother.

Jake took it goodnaturedly, only wanting his sister’s happiness. Evan did not; he had stolen more than one girl from me, and it was intolerable that Luke, his nerdy kid brother, would return the favor. Never mind that I hadn’t tried to steal her; she had come to me on her own. It still rankled him, and my amusement at his irritation didn’t help, either.

Why did she pick me? “Because you’re you.” It was as simple as that. She loved me for who I was, a sweet-natured, soft-spoken young man. I could be emotional, especially when surprised; my temper when my brother had stolen a girl from me the first time led to us getting into one of the few serious physical altercations we’d ever had. Evan’s athleticism might have won the day, but my rage let me get my licks in, and he was careful not to gloat the next time. His ego combined with the fact that he was my parents’ favorite, and therefore almost immune to consequences from them, meant there was a next time. Several next times, in fact.

Alli and I were well-suited to each other in so many ways. She was adventurous and outgoing, even if she often thought before she acted. I was a bit stodgy at times, making sure she kept her feet on the ground. I tried so many things in my college years that I never would have if it hadn’t been for her.

I wasn’t her first, but she was mine. Even if I hadn’t been smitten before that, I certainly would have been afterwards. But that affection was mutual; as we laid together afterwards, Alli held me close and told me over and over again how much she loved me, and how she wanted us to never part.

I had wanted that too, then.

“Dad?”

I was shaken from my reverie by Travis’s voice. “Sorry, buddy. What did you say?”

“Um ... How mad was Mom?”

Still dazed by the revelation, it took a moment to understand what he was asking. “Oh, um, she was fine, Trav. She was mad at first, but when I told her what happened, that you were wearing your helmet and pads, and it was just bad luck, she calmed down. She’s just glad you’re okay.”

Thank God I had talked to her before I saw that “B.” I hadn’t been the young man with the quick temper in quite some time, but I could feel his influence on me. I wasn’t angry at Travis; what his mother had done wasn’t his fault. But I was furious with her, and I don’t know that I’d have been able to hide it at all if I could hear her voice.

Trying to keep up the charade, I changed the subject. “What do you feel like having for dinner tonight?”

He wasn’t fooled, I don’t think. Trav was so insightful. So empathetic, like his mother. Even with a broken arm, he was more concerned about me than himself. But he played along with a half-smile and said, “How about Thai?”

Travis was my only son; he was bookended in age by his older sister, Julie, at seventeen, and his younger, Megan, at eleven. As we sat at the dinner table that night, I looked between my three children and ... Three? No, two, at most. I had raised him as my son, but did that make him my son? He was the son of my wife, but not mine. That made him my stepson, didn’t it? He had a father, but I had no son.

Did I have daughters? Did I have any children at all?

They looked like me just as much as Travis did. And where Travis was now so much more like his mother, they had always been similar to me. I was the primary caregiver in a lot of ways, and therefore the biggest and most constant direct influence on all three kids. Alli had traveled for her work since the kids were young, first in sales and then as a mediator, and my job hours as a contract programmer were flexible. It just made sense for me to handle the bulk of the child rearing.

The fact that the girls were so much like me didn’t come as a surprise. All the kids had bonded with me when they were younger. We were inseparable. Megan, especially, was still that way, not yet pulling away as the tween years began. She was very much Daddy’s girl. But even Julie never split from me the way that Travis did.

I didn’t think much of it before, because that’s what teenage boys do, right? They try to find the men they want to be by pushing against and away from their dads. But Travis hadn’t even really done that. There was no rebellion; we just weren’t close, and he was so different.

Travis had never been as interested in the things that I liked as the girls were. Videogames and programming and puzzles were a passion for the three of us, but they had never been more than a pastime to him, and they were barely even that now. That distance had now been cast into a new light, one that illuminated nothing but more questions.

Everything. Everything upended.

Alli was away for a week. I wondered if I would still be sane when she returned. I wondered how much more madness was still to come.

I laid in bed that night softly crying so the kids wouldn’t hear. It was all too much. So many questions with only one certain answer: at some point in the past, my wife had fucked another man and let me raise his child. Who? Why? How could she hurt me like that? Was it still happening? Was I a father at all, or just a caretaker for another man’s children? Did she love me? Had she ever loved me, or was it all some kind of cruel ruse?

I barely slept, and when I did, indistinct nightmare images haunted me. Taunted me, with my wife’s infidelity and my foolishness. Their specifics were forgotten in the morning, but not the dread that I felt.

The kids were sent on their way to school, and I sat at my kitchen table, trying to think. It was too big. Too many different possibilities, all of them clashing together in my mind and drowning out any kind of logic I could apply with pure noise. Finally, a moment of clarity came as I remembered my training.

When a programmer can’t figure out a problem and we have no one else to talk to, we’re supposed to still discuss it out loud. The technique is sometimes called “rubber duck programming” from the typical prop that many of us use, but anything can work: an action figure, a stuffed animal, or, if nothing else is available, thin air. It was the act of talking about the problem that made us slow down and collect our thoughts. Explaining it to someone else, even an inanimate object, made us go through the issue in as logical an order as we could.

So, I talked to myself.

“Stop, Luke. Stop. It’s a problem. Just another problem. Debug it. Break it into steps.” After taking a deep breath, I began to do what I did best.

“What do I know, and know for sure?” I sighed. “That Travis isn’t my son. He looks like me, but he’s not. So what does that mean?”

After mulling that over for a few moments, I continued. “He looks like me, at least superficially. Is that useful?” Not really; I looked like a bog standard European mutt with brown hair and eyes. But then a spark ignited, albeit only a small one. “Brown hair and eyes. Dominant traits. His father didn’t have blonde hair, and he didn’t have blue or green eyes, since those are recessive traits.” High school bio to the rescue again. I was looking for someone with brown hair and brown eyes.

“What else? Allison cheated on me at least once, roughly nine months before Travis’s birth. Things weren’t great between us back then, so maybe that was the only time? No. No. Focus on what you know for now, not supposition.”

I cast my mind back; that had been a hectic time in our lives. Allison had struggled with postpartum depression for a while after Julie was born. That plus her travel and my stress and Julie being a light sleeper and a colicky little thing meant we were not at our best during that period.

Our sex lives certainly suffered. There were months during that first year after Julie was born where nothing happened in the bedroom, and others where we just got off as fast as we could. Biological needs were barely getting met, and emotional ones weren’t doing much better.

All of that got worse when her brother got ill and Alli had to split time between her work, taking care of Jake, and our home. In fact, I had been certain, until that “B,” that Travis had been conceived on a blessed weekend when the stars aligned and my parents were able to take care of Julie while Alli was in town for three days straight, when we were finally able to reconnect as a husband and wife should.

“Okay, so something in the week or two before or after that weekend. What? Anything you can think of that might help explain ... oh, shit.”

Evan left town.

It was a couple months after Travis was conceived. My brother never made it to the NFL, only ever making a semi-pro team. Then he got injured, and even that last piece of his dream was taken from him. His dead-end job and the way he’d fucked up his love life made him an even more miserable SOB than he’d been before. It only got worse when he looked at his nerdy younger brother and saw him with a happy life, a job he enjoyed, and a loving family.

A sudden memory of his last visit to our house before he left chilled me. Alli had been there alone, and I came home just as he was leaving. The way he acted, which felt strange even at the time, now seemed sinister with the knowledge of my wife’s infidelity: the awkward body language; the way he lit out almost as soon as I got home, like he didn’t want to be around me, even as he was supposedly dropping by to say goodbye; and most of all, the strange look on his face when he thought I wasn’t looking, a mixture of pity, smugness, and disdain.

Oh God. Had he gotten what he wanted all along? Had he finally humiliated me by taking her away? And not just her, but my son, too? Is that why he doted on Travis during family get-togethers while he all but ignored my daughters? I felt sick, and the room started to spin.

“No. Stop. Think it through. Fight the anger, and don’t jump to conclusions. What do you know, not suspect? What other options are there?”

Trying to get back into the programmer’s mindset, I looked at other possibilities. “Alli traveled all the time for work; a random stranger maybe?” I chewed on that for a bit. “Mmm, that doesn’t sound like her, but she was so impulsive when we were younger. When did that really stop?” Fifteen years was a long time, but it was such a marked change in her behavior that it almost immediately came to me. “Travis’s birth. She changed then. Or ... no. Not after his birth. During her pregnancy with him.

So a fling while traveling, regretted afterwards? That would explain the explosive sex; but no, it wouldn’t, because we were always good together before the kids. A coincidence? Maybe. Maybe not.

“Would Alli bang a random stranger?”

Said a second time, it made even less sense. It just didn’t sound like her. She wasn’t a virgin, but she also hadn’t been promiscuous; Jake used to laugh about how hard it was for a guy to get a date with her. So probably not a random hookup.

“A co-worker?” I could think of at least two that would fit the bill, guys that looked enough like me that I could squint at Travis and see it. Couldn’t remember their names, though. “Bob...? Robert! And ... and Trent.” I rolled that second name around in my mouth contemplatively. “Trent. Trent. Travis? She wouldn’t, would she? Use the first couple of letters of her lover’s name to form his son’s name as a tribute? Or a joke on her stupid clueless cuck hubby?” Another deep breath to stop myself from going on a tangent. “Stop. Stop. Who else?”

I snapped my fingers. “Jake’s doctor! What was his name? Dr ... Bates? I think. Yeah. Yeah, Eric Bates. That’s ... fuck, that would make a lot of sense.” The guy was irritatingly handsome, and I knew they got pretty friendly when she was taking care of Jake; the few times I was around him I was annoyed by their closeness. I didn’t like the way he looked at her, and I liked even less the way she looked at him. Before, I wouldn’t have thought of it as anything more than me being unaccountably jealous; now, I suspected more.

Shaking my head, I continued. “Don’t get stuck on one possibility. Friends?” There were a few possibilities there: Jimmy Williams and Alan Taylor immediately sprung to mind, a pair of pussyhounds that had always shown too much interest in Alli. Our social life suffered during that first rough year with Julie, and we didn’t hang out often then. Or mine did, at least; was Alli actually traveling all those times she told me she was? Was she going away for work? Was she actually going out of town to meet someone else? Was she–

“STOP!”

I was still drifting from what I knew to what I could guess. I had at least a half-dozen strong possibilities and at the rate I was going, I’d get to double digits quickly. This wasn’t helping.

I needed more data. And I needed ... yeah. I needed someone to talk to. Talking to myself was a useful stopgap, but I needed someone to actually bounce ideas around with. However, I didn’t have anyone I could, at least not until I had ruled out some possibilities. With no idea who had done this– besides my cheating bitch of a wife– I didn’t know who I could safely talk to without alerting her.

Asking Alli would be pointless; in the years since Travis’s birth, she had been anything but impulsive. As a mediator, she’d leaned into her empathy for others and had combined it with a new self-control that meant that if she had any time to prepare at all– and possibly even if she didn’t, because she’d had more than a decade to think about how to deal with all this coming out– anything she told me would be suspect.

At the same time, if I gave her too much room to work in, and if she chose to lie to me, I was pretty sure Allison could come up with something on the spot. She was always quick-witted. I needed to narrow down the possibilities as much as I could. The fewer avenues she had to dissemble or mislead, the better my chances of getting an honest answer out of her.

There was a part of me that wondered why I even cared. She had cheated on me at least once, and without a very good reason– say, if it had been nonconsensual and she was too ashamed to tell me– there was no hope of reconciliation. But I needed to know, at the very least, whether any of the kids were mine. I couldn’t abandon them; they were innocent in all of this. I’d pay child support unless the father– or, for fuck’s sake, fathers– could be identified. They weren’t going to starve. But I wasn’t going to raise them either, pretending to be their father if I wasn’t.

That gave me the first good idea I’d had during all of this, the first real path to go down. If neither of the girls was mine, all of this was a moot point. And if they were all children of the same father, this affair had gone on for so long that I had to believe it was still ongoing. That would indicate ... what? An ex-boyfriend, maybe, or something even stranger. Crueler. My brother’s face popped back into my mind, but I pushed it aside.

I had the direction I needed to start with, and I knew exactly who could help me. An old friend of mine from college had gone into biotech instead of business dev, and he’d made a pretty penny offering his services to various companies.

Tate also was never really friends with Alli. There was no animosity there, but they just never clicked. And arguably even more useful, Tate was about as gay as the day is long. There was no way that he’d ever have fucked Alli, not with a dance club’s worth of Molly and an IV of Viagra. I couldn’t see him covering for anyone, either; his own husband had cheated on him, and he had absolutely no patience for adultery. Tate was the closest thing I had to a safe bet, and a quick phone call to him confirmed he could get me tests for all of the kids with a turnaround of less than a day.

I was too frustrated to work. There are people for whom burying themselves in their jobs can help them keep their mind off of problems elsewhere, but I’ve never been one of them. There was space for a single problem at a time in my head, and while I could sometimes switch to another one if the needs were pressing enough, it was difficult. And this problem? There was nothing that was going to get my mind off of it.

The good news was that I was only in the planning stages for my most recent contract. I could afford a little slack time for now, planning to make up for it later with long hours. Or maybe not. Slippage in software development isn’t just factored in: it’s almost expected. I knew more than one guy who came through some personal crisis and made up for it on the back of caffeine, rage, and deadline anxiety. Hell, I’d been one a few times. I guessed I would be again.

The bad news was that, even with the knowledge that this was the path forward, I still could find only limited comfort in that fact. It was all so awful, and my future so murky, that I couldn’t even decide what the worst case scenario would be.

If none of them were my kids, I could walk away with little regret. I’d still try to keep in touch with them, and part of me would always love them, but I’d have no real allegiance. That might sound cold, but it was true. They would all be my stepchildren then, and how many stepdads stay in their stepkids’ lives after finding out their mom has cheated on them for over a decade?

But if one or both of the girls was mine, what then? What if Travis was my brother’s son? What if Alli had been raped and was too embarrassed to tell me? Would I believe that? How could I trust anything she told me? How could I trust almost anything at all?

I sat there at my kitchen table, skipping breakfast and lunch, until it was time to pick the younger kids up from school. All I could do was obsess. I had come to no conclusions, unintentionally added about a dozen possible names to my list, and only made myself unhappier. Fuck! I wanted to strangle her.

Once the kids were home, it got easier. There was someone else that needed me to keep it together then. Three of them, actually. I wasn’t the best actor, but I relied on my affection for the kids. My love for them. Depending on how things ended up, they might be about to have the worst time of their young lives, and if I could soften the blow for them, I would.

I made spaghetti. My cooking repertoire is fairly limited, but I liked cooking Italian. The kids always loved my spaghetti. After dinner, I made sure to spend extra time with them, even Travis. Especially Travis.

I felt so bad for him, maybe even worse than I felt for me. It wasn’t his fault, but he was right at the center of a storm that might destroy his family, and I knew how sensitive he could be. He’d blame himself for it, no matter what happened. He was just that kind of kid.

It was one of the things I was proudest of about him, that sense of personal responsibility, even if he did take it too far at times. He might be impulsive, but he always faced the consequences, even sometimes when they weren’t really his fault. God, what was coming would crush him.

As we spent time together, I looked at my son ... stepson, really looked at him, in ways I hadn’t for a while. When someone’s close to you for so long, your brain starts to skip over little details about them: their personality quirks, their tics, the little physical aspects that start to blend into the background.

It’s easy to keep assumptions and impressions, to not question them because they’ve been with you for so long. But as I looked at Travis then, I saw more and more the ways we differed. I always thought that he had my chin and nose; maybe a little rounder, maybe not quite as defined, but that could have been down to his youth or his mother’s influence.

But now, I knew that I had no influence there at all. I could see how my belief that he was my son had made me miss the subtle differences in our features. The girls shared my chin and nose, and they were very clearly mine. But his? No. I realized for the first time that even a blending of his mother’s features and mine wouldn’t account for the differences.

There were tics I didn’t recognize, too, ones not from me or from Alli: the way one corner of his mouth quirked up more than the other when he smiled; an almost OCD-like need to do things evenly, in twos or fours or eights; his laugh, so different from ours. How much was nature? How much was nurture?

And why did some of it seem so familiar? Who did I know from the past that acted like this, that smiled like this, that laughed like this? Anyone? Or was I just driving myself mad trying to find clues that didn’t exist to solve a mystery I had no chance of figuring out?

The next morning, we went to the lab. I made up a bullshit excuse– a specialist doctor’s visit– but none of them really bought it. Julie and Megan just rolled with it, because, hey: morning off from school. But Travis definitely suspected something was up. He knew that I’d been acting differently since his accident, and while he dropped it when I told him it was just to do some followup testing– something to make sure that all of us were safe from an anomaly found during his blood test– I could tell he didn’t really buy it.

After dropping them at school, I used the rest of the day to do chores and yardwork. I didn’t need to think too hard about the work, but I could also use the exertion and the minimally necessary attention to detail to distract myself. It was certainly better than nothing. Then it was time to pick the kids up again. Time to perform my pantomime. Time to toss and turn in my bed, wondering how many more days I’d be sleeping in it.

The test answered several questions. The first, and most important, was that Julie and Megan were mine. That was a mixed blessing; almost entirely a positive, of course, but it meant that one of the easier routes was closed off to me, the one where I washed my hands entirely of their mother and our family. That simple scenario, dark though it may have been, appealed to me in the late hours where I wanted for this to all just go away. But I’ll admit that I wept openly knowing that something in my life and marriage had been real.

The next was, honestly, a real surprise. My brother had been the frontrunner as Travis’s father in my mind; the way he’d acted before he left, how he used to steal girls from me, his anger when Allison picked me over him, and just that he was generally an asshole all pointed to him. But he wasn’t Travis’s father, nor was one of my cousins or any other member of my family. Another source of easy relief taken from me; if it had been him, I would have had so many questions answered. But instead, I was almost back at square one.

Tate was able to help me a little bit more, though. He had access to various genealogy and consumer-grade DNA databases; I didn’t ask how, and he didn’t say. We were able to strike a few people who were already in these: Robert Jenkins, Allison’s co-worker from that time; Alan Taylor, one of our creepy “friends” from our younger days; and Dr. Eric Bates, her brother’s oncologist.

That still left a lot of people, and finding out the girls were mine didn’t actually rule a longer-term affair out, either. Travis could have been an oops that she learned from, or she could simply have not cared who fathered each child, as long as I didn’t find out. Or maybe she didn’t even really worry about that. Maybe she just believed that I was trusting enough to never catch her. To be fair, she would have almost been right.

That was the most maddening thing, even more than the infidelity itself: I simply had no basis for what was real and true anymore. I believed that Allison loved me– she certainly acted like it– but I had thought that before my fateful discovery as well. Clearly, for at least a little while there, she hadn’t loved me enough to stay faithful. It had been a hard time for both of us, I know; but did that even begin to excuse it? I sure as hell didn’t feel like it did.

And she hadn’t been loving enough to fess up, either. She had to have known; once I started looking, it became obvious that Travis wasn’t mine. Did Alli lie because she didn’t love me, and she wanted to keep her happy life while she continued to cheat? Or did she lie because she did love me, wanting me to keep my happy life, to not lose it because of a one-time indiscretion that produced lifelong consequences? I just didn’t know.

There was nothing that could be taken for granted anymore; she had lied to me for at least sixteen years, since the day that Travis was conceived. That meant that any “knowledge” that I had of who my wife was simply wasn’t knowledge at all. It never had been. It had only ever been belief that Alli was who she told me she was.

Maybe that’s true for everyone, but I wanted to believe that I really knew who she was, that she was open and honest with me about everything that really mattered. I had been with her, and now that I knew that honesty hadn’t been reciprocated, the possibility that she might have lied to me about any and everything was slowly driving me mad.

My behavior became even more obsessive as the week wore on and as answers stubbornly refused to present themselves. I looked in her email accounts; we’d shared our passwords with each other for years. Nothing. My job made me far more knowledgeable about computers than Alli, so I scoured our shared home computer for any sign of hidden files, apps, folders, or strange activity. Nothing.

Our bank accounts fell under my scrutiny next as I looked for any strange transactions or cash withdrawals. Nothing. I checked her cell phone records. Nothing. The house was searched from top to bottom during the week that I awaited my wife’s return, looking for even the most circumstantial evidence of a separate life hidden from me. Nothing.

When she called during the week, I did my best to quickly hand off the phone to one of the kids. I don’t think Allison suspected anything; she didn’t know that I knew, so why would she? There was always something to do at home, and she’d praised me in the past for how hard I worked at keeping all of the balls in the air when she wasn’t there. Alli always bragged about what a great dad I was. When I thought about that after the revelation about my son ... stepson, I wanted to throw everything she owned in a wood chipper. ‘What a useful little cuck he is.’ Is that what she was really saying?

Even our past was in question, all the way back to the first time we met. Why did she pick me? “Because you’re you.” It had always seemed so sweet and sincere when I’d thought about it before. Now, it carried sinister undertones. ‘Because you’re such a sucker.’ Everything she had ever done, every little glance and gesture, every phrase that could even slightly be open to interpretation, every time we’d shared anything, it was all suspect.