Set in a small Cornish seaside town on December the third, there is a sudden change in weather from autumn to winter. A war veteran, Nat Hocken, living in the town and working part time for a farm owner notices a large number of birds behaving strangely along the peninsula where his family lives. He attributes this to the sudden arrival of winter. That night, he hears a tapping on his bedroom window and encounters a bird. This bird has only drawn blood on Nat's hand, but as the night progresses he encounters more birds, especially flocking into his children's room. The birds are defeated by dawn. He reassures his wife that the birds were restless because of a sudden change in the weather.
The next day, Nat tells his fellow workers about the night's events, but they place no importance on his warning. As Nat later walks to the beach to dispose of the dead birds, he notices what appears to be the white of the waves on the sea, but is actually a great line of packed seagulls waiting for the tide to rise. When Nat arrives home, he and his family hear, over the radio, that birds are attacking all over Britain, presumably because of the unnatural weather. Nat decided to board up the windows and chimneys of his house. He notices more birds, including the gulls, above the sea waiting for the tide. He rushes to pick up his daughter, Jill, from the school bus stop to save her from the approaching attack. On his way back Nat spots his boss, Trigg, who has a car, and persuades him to give Jill a lift home. Trigg cheerfully professes to be unfazed by the announcements and plans on shooting at the birds for fun. He invites Nat to come along, but Nat rejects Trigg's offer and continues home, knowing that hunting them would be futile. Just before he reaches home, the gulls descend, attacking him with their beaks. Luckily, Nat manages to reach the cottage with only minor injuries.
Soon, massive flocks of birds attack. A national emergency is declared on