One very important and pertinent question remained. Why did Mantell, an experienced pilot, try to go to 20,000 feet when he didn't even have an oxygen mask? If he had run out of oxygen, it would have been different Every pilot and crewman has it pounded into him, "Do not, under any circumstances, go above 15,000 feet without oxygen." In high-altitude indoctrination during World War II, I made several trips up to 30,000 feet in a pressure chamber. To demonstrate anoxia we would leave our oxygen masks off until we became dizzy. A few of the more hardy souls could get to 15,000 feet, but nobody ever got over 17,000. Possibly Mantell thought he could climb up to 20,000 in a hurry and get back down before he got anoxia and blacked out, but this would be a foolish chance. This point was covered in the sighting report. A long-time friend of Mantell's went on record as saying that he'd flown with him several years and knew him personally. He couldn't conceive of Mantell's even thinking about disregarding his lack of oxygen. Mantell was one of the most cautious pilots he knew. "The only thing I can think," he commented, "was that he was after something that he believed to be more important than his life or his family." My next step was to try to find out what Mantell's wing men had seen or thought but this was a blind alley. All of this evidence was in the ruined portion of the microfilm, even their names were missing. The only reference I could find to them was a vague passage indicating they hadn't seen anything. I concentrated on the canopy-reflection theory. It is widely believed that many flying saucers appear to pilots who are actually chasing a reflection on their canopy. I checked over all the reports we had on file. I couldn't find one that had been written off for this reason. I dug back into my own flying experience and talked to a dozen pilots. All of us had momentarily been startled by a reflection on the aircraft's canopy or wing, but in a second or two it had been obvious that it was a reflection. Mantell chased the object for at least fifteen to twenty minutes, and it is inconceivable that he wouldn't realize in that length of time that he was chasing a reflection.