International tycoon Alfred Loewenstein, 52, flying from London to Brussels with a pilot, copilot, valet, male secretary, and two stenographers, disappeared from his Fokker Trimotor on July 4, 1928. A few days later, his body was discovered by French fishermen. Norris treats the question Did Alfred fall or was he pushed? as a kind of Agatha Christie locked-room mystery--although unlike Dame Agatha he does not come out absolutely and put a noose around anyone's neck. In his 40s, Loewenstein had appeared like a financial meteor, swooping about, gobbling up companies and becoming briefly the most astounding figure in world finance, always with 50 deals balanced aloft at once. He also seems to have been a manic depressive--but a manic whose dreams of grandiosity had become real; although during the week before his death, his vast fortune had been halved by a failed scheme. And here is where the motives for murder start to rise. First of all, was he murdered? The door on a Fokker Trimotor closed and opened like a screen door on two small hinges, and locked on a spring latch. It also had two small draw bolts--just a joke of a door. But most important! Because of wind pressure (it was later tested by an insurance company) the door could not be opened from within much more than six inches, and then only by main force. Ergo, it was impossible to fall out accidentally. What's more, the pilots reported that they had each easily opened and closed the door in separate tests during the fatal flight. Why such tests, if they even were? Who knows? In any event, his body when found wore only shoes, socks and shorts. The pants and jacket were not on board the plane (had he been poisoned and vomited on them?). In their stories, his retinue pretended that he just disappeared into the toilet for 10 minutes, they'd got worried and went looking for him. But since it is physically impossible for the door to open without wildly altering the cabin's air pressure, Norris assumes that everyone on board knew what happened. He traces their later lives and possible motives and also those of Loewenstein's wife and closest business associates. One must judge his varied conclusions for oneself. A wobbly Maileresque opening, but once underway a brilliant detective job.