While dissension among Xindi ranks festers, Degra gets Archer returned to Enterprise. Archer considers compromising his morals to restore Enterprise's warp capacity after a fleet of Xindi-controlled warships cripple the vessel's engines. Sacrificing his ethics, he attacks an innocent alien ship to get their warp coil to repair the Enterprise's engines and intercept the Xindi superweapon. Meanwhile, T'Pol grows increasingly volatile, prompting her to confide a troubling secret to Phlox. Trellium-D exposure led to her addiction, with withdrawal symptoms weakening her emotional control.

Before attempting to use a Xindi subspace corridor to reach the Xindi council, the Enterprise crew faces a bizarre encounter with their own descendants on an Enterprise. Captained by T'Pol's son Lorian, the ship warns Archer of an alien attack by Kovaalan ships. Enterprise escapes into the subspace corridor, but attack damage destabilizes the corridor, causing a time shift with the ship emerging in 2037. Will foreknowledge change anything?