Special agent Harry Tasker gets out of the water outside a heavily guarded mansion, takes off his wetsuit, and there is a dinner jacket underneath. Harry strolls into a swanky party. Harry meets with Juno Skinner, steals some computer files, and escapes in a blaze of gunfire. He's picked up by his partner, Albert "Gib" Gibson, and they return to the United States. Harry goes home to his wife Helen. Helen doesn't know what Harry does because he pretends to be a computer salesman. Their 14-year-old daughter Dana is a sullen teenager, and Helen is so bored by the routine of her life that she's on the verge of having an affair with used-car salesman Simon, who claims to be a spy. Harry is hot on the trail of a group of terrorists led by Salim Abu Aziz. Aziz and his men are smuggling nuclear weapons into the USA in pieces of Persian art, and Aziz plans to hold the country hostage in the name of the Crimson Jihad. Harry's also out to save his marriage when he discovers Helen with Simon, who still claims to be a spy. Harry uses the Agency's resources to give Helen a taste of the real thing. Harry blackmails Helen into seducing an enemy agent -- Harry himself -- in a hotel room, but their tryst is interrupted by Aziz's men, who kidnap them and take them to one of the Florida Keys, where they're preparing to detonate their nuclear bomb. Harry escapes and rescues Helen, and then they discover that Aziz has gone to Miami and kidnapped Dana. Harry uses a harrier jet to get to Miami, where he sets out to rescue Dana.