ENT Season 2 Episode 26 The Expanse

Plot

In April 2153, an alien probe attacks Earth, cutting a destructive swath 4,000 km long, from Florida to Venezuela, killing millions, including Commander Tucker's younger sister, Elizabeth. Enterprise is recalled to Earth by Admiral Forrest. On the way, Captain Archer is kidnapped by the Suliban Cabal. He accuses the Suliban leader, Silik, of being responsible for the Earth attack, but Silik professes ignorance. The Cabal's sponsor, a vague and shadowy holographic human from the distant future, informs Archer about the Temporal Cold War and the Xindi, the race that attacked Earth. He claims the Xindi have been told by another Cold War faction that their home-world will be destroyed, in 400 years, by Humans.
Enterprise is again ambushed, attacked by a Klingon Bird of Prey commanded by Captain Duras at the behest of the Klingon High Council. Fortunately, three other Starfleet vessels arrive, forcing it to retreat. Archer relates his encounters to Starfleet and the Vulcan High Command, and it is clear that the Xindi of the present are pre-empting the destruction of their home-world in the future. Ambassador Soval is dubious of Archer's temporal war argument, and tries to dissuade him from venturing into the Delphic Expanse, a dangerous section of space that once destroyed the Vulcan ship Vaankara.
Archer, acting on advice from the shadowy informant, scans the crashed probe, revealing a component with an unmistakable date stamp placing the date of construction at 420 years in the future. Starfleet orders Archer to take Enterprise to the Expanse to try to stop the Xindi. Starfleet refits the Enterprise with improved weapons, shields, and a detachment of MACOs (Military Assault Command Operations soldiers) are stationed aboard for the mission.
Ambassador Soval informs T'Pol that her assignment on Enterprise has been terminated by the High Command, who deem this to be purely a human matter. T'Pol logically points out that if they needed a Vulcan on the Enterprise before, they are in greater need now, so her assignment should be continued. She debates, but does not disobey. Enterprise begins their journey towards the Expanse, and to return T'Pol to Vulcan. They are again attacked by Duras, but Archer retaliates using his new torpedoes at 10% and then 50% strength. The Klingon warbird limps away. T'Pol reveals she has resigned from the Vulcan High Command and wishes to stay on the ship. After she tells Archer that "you need me", the detour to Vulcan is cancelled.
After a three-month journey, Enterprise nears the Expanse and is again attacked by Duras. Archer decides to use the 100% setting on his torpedoes, and Duras' ship is destroyed. The Enterprise continues on into the Delphic expanse.