Doc has everything a border collie could possibly wish for. Two humans he loves, sheep to herd every day, squirrels to chase... until one terrible night changes everything. A vampire kills his humans, banishing Doc to a sheep-less new life in the city. Out for revenge, Doc has to hunt for clues while avoiding both the Stray Gang and the Catcher, all while keeping his quest a secret from his new human. His luck finally changes when he finds a kitten named Mika, who reeks of vampire. Together with some two-legged help, Doc and Mika must track down and stop the vampires once and for all.