The Quapep module was a large, floating artificial habitat, one of hundreds of biomes making up the Web of Worlds in the First Federation. It was located within the atmosphere of the class J gas giant Cherela.
In 2269, as attempts were made to stabilize failing antigravity systems in all of the biomes in the Web of Worlds, Koust, Targus and Leonard McCoy assisted a team in the Quapep module to install a remote control device. They arrived during a thunderstorm, and struggling systems left the module feeling like it was tilted, making walking difficult. Targus' head was struck by a boulder, and as McCoy hurriedly worked to to save his life, Koust realized that it was possible to be a warrior to save lives. Koust took the transmitter from McCoy and completed their assignment. (TOS novel: The Face of the Unknown)