Workers on P3R-118 were given a memory stamp which erased all past memories and replaced them with a new personality, ensuring compliance as they labored in an underground facility to supply power to the domed city above. If the procedure failed and past memories began to return, the workers were said to be suffering from nightsickness and were subjected to the memory stamp again.

Cross Reference: Brenna, Calder, Carlin, Jona, Kegan, Memory Stamp, P3R-118, Therra, Tor

Episode Reference: Beneath the Surface