Spirited New Yorker Linda Voss goes to work for international lawyer and secret Office of Strategic Services operative Ed Leland just before World War II. As they fall in love, the United States enters the fight against Hitler, and Linda volunteers to work for Ed spying undercover behind Nazi lines. Assigned to uncover information about a German bomb, Linda also has personal motives to fulfill: discovering the fate of her Jewish family members in Berlin.

At the opening party of a colossal—but poorly constructed—office building, a massive fire breaks out that threatens to destroy the tower and everyone in it.