The Mercury defended Earth against the Borg in the year 2373. In 2376. the Mercury was at Earth to pick up Commander Deanna Troi for a diplomatic mission to Gorn space and to Ferenginar. The Mercury was able to take Gorn vessels to rendezvous with Captain Jean-Luc Picard's fleet. The Mercury fought in the Battle of Rimbor against the Petraw fleet and was subsequently damaged. The USS Enterprise-E towed the Mercury back to Federation space. (TNG - Gateways novel: Doors Into Chaos; TNG - Gateways short story: "The Other Side")