On Erin Island, an idyllic fishing village off the coast of Ireland, charming inebriate Ciaran O'Shea (Richard Coyle, Pusher) is tasked with showing straight-laced police officer Lisa Nolan (Ruth Bradley, Primeval, in Her Skin) her new beat. Not that there's much to police, as most of the community's troubles are caused by O'Shea himself. But strange doings are afoot: The crew of a fishing boat disappears, whales start appearing dead on the shore, and a local lobsterman catches a mysterious tentacle creature in his trap. Soon it becomes clear to O'Shea and Nolan that there's something unnatural out there, and that it's hungry. So it's time to rally the villagers, arm the troops... and head to the pub.