The USS Gantry was a Starfleet vessel in service in the early 25th century. In 2409, the Gantry was infested by a race of 1-meter tall aliens dubbed gremlins. The infestation resulted in a loss of mental capacity for the crew, setting the Gantry on a collision course with Earth Space Dock.
The ACI, working with Troian crewmember Gregnorah Fahnan, who was not infected, managed to restore the crew and prevent the destruction of the Gantry. (Episode: Gremlins in the Grapes)