Grayson Trent

"Grayson Trent" was an alias used by a Romulan Spy while infiltrating the Federation in 2311. Trent was assigned to the USS Enterprise (NCC-1701-B) as Chief Computer Scientist and held the rank of Lieutenant. Captain John Harriman discovered that Trent was a spy almost immediatly after Trent boarded the ship, but with permission of Starfleet Command allowed him to remain on board to see what the Romulans were up to. The crew was not made aware of this though. Later that year, Demora Sulu became suspicious that there was a Romulan Spy on Enterprise and Admiral Mentir revealed that Trent was indeed a spy, agreed that his usefulness had diminished, and ordered him captured.

It is unclear whether "Grayson Trent" is an actual Starfleet Officer who the Romulans captured and replaced with one of their agents, a product of computer forgery, or a deep cover operation.

(TLE novel: Serpents Among the Ruins)