Upon realizing that her lover is a vampire, Alice decides to try to kill him. He doesn't seem to mind. Note: Though coded violent, the acts of violence are rather minimal.
Maggie and Jemma are lovers, and share a secret passion for S&M, as well as vampire stories. But even lovers can have darker secrets...and darker desires.
Magic leaks through a rift in the barrier between the human world and Hell. Demons, vampires, harpies, and other monsters come through that rift. Closing the rift to seal out the monsters would also shut off the source of magic, but nobody wants to do that because of the wondrous changes made possible by magic. This is how the problem is solved after 2,000 years of trying.