The Temporal Cold War begins before the opening credits. A Klingon courier named Klaang is shot down in Oklahoma while carrying a vital data module. We later learn his attacker is a Suliban—a genetically engineered humanoid from the 28th century—under orders from a mysterious "Future Guy." Captain Jonathan Archer is tasked with returning Klaang to Qo’noS, unknowingly stepping into a temporal proxy war.
As the show moved into its final season, it had to wrap up the messy Temporal Cold War to make room for more traditional prequel storytelling. star trek enterprise time travel episodes
Enterprise’s series finale is itself a time travel episode, and one of the most hated in Trek history. Set six years after the previous episode, the story is framed as a holodeck simulation on Star Trek: The Next Generation’s USS Enterprise -D, with Commander Riker reliving the final mission of Archer’s crew. The Temporal Cold War begins before the opening credits