Police officer Lisa Nolan comes to Aran Island, Ireland, to take charge during a colleague's two-week holiday. Simultaneously, blood-thirsty, sea-dwelling aliens arrive at the quiet island to propagate. As dead whales wash up on shore and people start mysteriously disappearing, officers and a few locals slowly discover their peril along with one sure defense - high blood alcohol levels, which the aliens can't stomach. As a storm approaches, enabling hungry hatchlings access to the locals, an open bar kicks off a desperate bid for survival as inebriated police and friends stagger to remain cognizant long enough to thwart the alien invasion.