Guests at an old English manor house are stalked by a mysterious killer known only as "The Terror".

After socialite Lynn Llewellyn receives an anonymous threat, he is poisoned at his uncle's casino, and although he recovers, his wife is murdered by the same killer.

Madge Winton, a beautiful secretary, makes herself look homely in order to avoid advances by lecherous bosses. When her new employer, writer Freddy Matthews, accidentally sees her without her disguise, she has to pretend to be her roommate Sadie.

A lighthouse keeper and his daughter are in trouble on two fronts--if the authorities find out he is going blind they will remove him, and a gang of liquor-smugglers is trying to destroy the lighthouse so they can land their illegal cargo on shore without being spotted.