IF YOU TOOK A LARGE NUMBER OF FLYNKS—FLYING, AUTONOMOUS chain links—and joined them together into a long chain, and connected its ends to make it into a continuous loop, and then got the whole loop moving through the air like a train composed of little airplanes, each using its stubby winglets to generate its share of the lift, then you had a thing known as an "aitrain," pronounced the way a resident of Old New York would have said "A train." The concept was old enough that its etymology had been obscured by time. It might have been "air train" with the first r elided, or a contraction of "Aitken train." Sometimes, as here, it was a captive aitrain, passing continuously through a fixed installation on the ground and rising from there to a considerable altitude before reversing direction and plunging back down for another circuit. But aitrains could also fly freely in the air: a technology crazy enough that it had become associated with the Aïdan big-brains known as Jinns, or Ghenis, and tended to be used only by Red.