Inside the hangar, Steve sees his former love, test pilot Jenny Fraser, (Suzanne Somers) and greets her with a deep kiss. Their romantic interlude is interrupted by the two men who clues Steve iup on the built-in components designed to render the aircraft invisible on radar screens.

Vail's assistant, Hal Martin, (Robert Hogan) brings the data that confirms that all systems are go for a test flight tomorrow.

They leave the restaurant to go down to the parking lot where they run into Arthur (Jim Begg), a funny drunk whose car is blocking Steve's. Jenny offers to call his wife while Steve hooks the car's rear bumper to a granite ashtray to make sure the man doesn't drive off in his inebriated state.

He reports the incident to Jenny and Rudy. Both are stumped as to the reason why they'd want to destroy the back-up and not the original aircraft, which Jenny is scheduled to test this afternoon. For Jenny's safety, Steve offers to take over the test flight. But seeing how Jenny is better qualified for the mission, he grudgingly bows down but insists on supervising the operation.

Panic runs through the room when her plane fails to register on the radar once she turns off the device. Steve urges her to land the aircraft immediately, but gets no answer.

Back at the control room, Steve and the team of engineers lose themselves in conjectures as to what might have occurred. Steve proposes to repeat the operation using the sister plane, but seeing how the risks for his safety are too high, they suggest to fly the plane by remote control instead.

They follow the plane at a distance in an helicopter. Minutes after activating the device, the aircraft explodes before their eyes.

They land next to the burning wreckage to sift through the rubbles in search of the black box.

Meanwhile, Rudy is informed that a call had been placed from Vail's office to Wilfred Damien (Stanley Waxman), a notorious criminal involved in the theft of innumerable top classified documents. Steve is baffled as to what Vail could be selling Damien since both planes have allegedly been destroyed.

He hurries over to the infirmary where Vail insists he's innocent. After reviewing the latest events, he suspects that his assistant might be responsible. When Steve calls the authorities to have Martin apprehended, they inform him that he's already left the base.

Steve surveys the area where Jenny's plane last disappeared. He zooms in on a small airfield where he spots the missing aircraft.

Steve manages to break free but too late to stop Jenny from taking flight aboard the doomed aircraft. He throws a net over the crooks and takes off after Jenny.