Archer seeks the Aquatics' help as the Reptilians force a captured Sato to arm the weapon, and Major Hayes dies rescuing her.
The Reptilians implant Sato with neural parasites to force her to supply a code needed to arm the weapon. Major Hayes leads a MACO team, supported by Reed, to rescue her from a Reptilian ship, and Hayes is fatally shot covering the others' escape, naming Reed as his successor before he dies.
Archer persuades the Xindi Aquatics to join the fight, but spatial distortions created by the sphere beings hamper the allied fleet. Dolim sends the weapon through a vortex toward Earth and destroys the doubting Insectoid ship, and Archer follows in Degra's faster ship. The episode was directed by Robert Duncan McNeill and written by Andre Bormanis and Chris Black.