The Tachyon Recreation Generator (or TRG) was a device created by the Argolins in the hopes of rejuvenating themselves and saving their race from sterility. The technology, however, was flawed and it only resulted in a single clone, Pangol. The device was later used for playing games at the Leisure Hive. Mena brought in Hardin to get the TRG to work properly, and when it was tested on the Fourth Doctor it aged him five hundred years. Pangol planned to use the TRG to create an army of clones of himself with which to restore Argolis to its former glory. This plan was defeated by the Doctor, who used components from the randomiser to alter the TRG so that it rejuvenated himself, Mena and Pangol. (TV: The Leisure Hive)