A Star Trek: The Next Generation yarn from the fantasist (The Door into Sunset, p. 28) and veteran of numerous Star Trek hardcovers. Duane's first stab at a Next Generation tale is based on an old Star Trek episode, ``Mirror, Mirror,'' in which Kirk, Scott, and Uhura were propelled into a parallel universe where the Federation was a ruthless empire; their personal counterparts, with whom they had exchanged places, turned out to be brutal barbarian warriors bent on conquest and loot. This time, the Enterprise—with Hwiii, a dolphin scientist, aboard—is switched into the same universe visited by Kirk, and finds itself confronted by a counterpart Enterprise, bristling with weapons, of superior speed and power. Now Captain Jean-Luc Picard must defeat his evil twin and prevent the invasion planned by the other, malign, Federation. Anyone who saw the original episode knows more or less what to expect. Given the large first print run, the publishers obviously expect demand to be brisk—but, workmanlike, unsurprising, and mediocre as it is, will it play in Peoria? (First printing of 200,000)