The Old Ones have arrived and are intent on taking over the world by force. Cutler has other plans, but when they go awry, his revenge on his own kind is plotted. Annie is conflicted and upset as she comes to terms with the fact that, in order to save the world, she's been tasked with the most difficult decision of her afterlife. Tom and Hal have their own plan to destroy the vampires, but when Mr. Snow (Mark Gatiss), the vampire leader, visits Hal he demonstrates the power he holds over our hero.