The fourth Federation starship to bear the name Enterprise, an Ambassador-class vessel, registry number NCC-1701-C. The Enterprise-C was lost and presumed destroyed near Narendra III in 2344. In that year, this ship, commanded by Captain Rachel Garrett, responded to a distress call from the Klingon outpost on Narendra III. The outpost was under a massive Romulan attack. During the battle, a torpedo explosion opened a temporal rift, and the Enterprise-C was sent some 22 years forward in time. This proved to be a focal point in history. With the Enterprise-C gone from the "normal" timeline, an alternate timeline was formed, in which the Federation and the Klingon Empire engaged in an extended war. The Federation was near defeat by 2366, when the Enterprise-C emerged from the rift, encounting the Enterprise-D.
It was soon realized that the Enterprise-C had to return to its proper time if history was to be restored and the terrible war with the Klingons was to be averted. The tragedy of the war was emphasized when a Klingon attack resulted in the dead of Captain Garrett, after which the Enterprise-C officer Lieutenant Richard Castillo agreed to assume command of his ship and return it to 2344. Enterprise-D officer Natasha Yar, who was still alive in this timeline, volunteered to return with Castillo to help defend Narendra III against the Romulans. All Enterprise-C personnel understood that returning to the past was a virtual suicide mission because of the intensity of the Romulan attack on Narendra III. Once the Enterprise-C returned through the temporal rift, the time flow returned to normal, and history was restored to its proper shape.