Lieutenant Grey was a Starfleet officer who served aboard the USS Excelsior in the 2290s. During a mission to save Commander Pavel Chekov, Grey reported that the dilithium crystals aboard the Excelsior were fracturing. Just as the Excelsior was about to save the USS Enterprise-A and the USS Ranger, the last crystal broke and Captain Hikaru Sulu and the crew were thrown into the mirror universe. When they woke up after they entered the mirror universe, they encountered Chekov's mirror counterpart on the ISS Enterprise, who tried to kill them. They escaped, and had to fight parallel versions of friends and foes to reach the Janus Ultima Vortex. (TOS video game: Shattered Universe)