It was the old bomber-interceptor game. That other F-94 could have been an enemy bomber, plowing toward American cities with a load of atomic death-- Smitty turned his head and looked back. His eyes crinkled into a smile under the green glaze of his goggles. Smitty. Captain Daniel Purcell Smith, then--or "D.P." Smith, which were also the initials for "Displaced Person." A cool, thoughtful, and smart jet-fighter pilot in those days, and a darned good guy. They had taken Seattle apart at the seams on their one furlough, preferring the devilment of their own companionship to going home to Mom's apple pie. Morrow's telegram had made sense, all right. The words _scramble_ and _May Day_ were fighter-lingo; _scramble_ meant _let's go! we've a fight on our hands_, and _May Day_ meant _I'm in trouble!_ He was in trouble, certainly. The mechanism he'd developed was, in itself, plenty of trouble. And it was a special kind of trouble--the kind in which the only person he could dare trust had to be someone like Smitty. The Air Force camaraderie which existed between them had never quite faded out. Even after they'd been mustered back into civilian status, after Morrow had signed a government engineering contract and Smitty had gone on to commercial flying, they had kept in touch with each other. Diverging interests hadn't pulled them apart; the old school ties, the old trustworthiness was still there. An odd letter every few months or so, a postcard at Christmas.... He was fortunate to know a man like Smitty, Morrow knew. He couldn't have carried out his plan alone. He reached home, stored his motor-bike in the garage, and walked into the living room. He snapped on the light and stood there for a moment, gazing across the room at his littered writing desk. If he were going to carry out his plan, there was one thing he'd have to do himself. People weren't going to like it. Good engineers were scarce. He walked across the room, sat down at the desk, and crammed a sheet of Western Electronics stationery into his portable typewriter. He paused, lighted a cigarette, and then grimly proceeded to write his letter of resignation. * * * * * "It's a mechanism that floats in the Earth's field of gravity," Morrow began-- They were seated in a secluded booth in the modernistic restaurant at the Newark Airport. Through the wall-length observation window, they could look down on the airfield; a giant stratoliner was rolling up before the building, the bright spot-lights glistening off the silvery arcs of its six big turbo-props. White-uniformed linemen were pushing the steps up to the side of its fat hull as the door slid open and a pert stewardess poked her head out. Beyond the gleaming sky-monster, in the pitch darkness of early morning, the runway lights twinkled in rows and patterns of red, yellow, blue and green sparks.