The British electrify the waters off the Irish coast which drive the Gorgo creature and its infant west until they rest off the east coast of America. The baby Gorgo fouls the trans-Atlantic telephone cable so divers go out to fix it. Alerted to the presence of Gorgo, the creature is attacked and finally incapacitated in a sandpit while the mother is sleeping. When she wakes up and finds him missing, she attacks New York city. The world's weakest Hydrogen bomb is dropped on Gorgo which not only fails to damage New York, it doesn't kill the monster. One of the divers who initially found the baby Gorgo waves flame at its snout so it will break free of the sandpit and they can use smoke to drive it out to sea. Two cannon shells are loaded with a nerve agent, one for mama and one for baby, and are fired into them. Baby Gorgo collapses, but mama scoops him up and returns to the sea floor. The men think the nerve agents have killed them, but they are merely snoozing.