ENT Season 3 Episode 23 Countdown

Plot

Needing a third species' codes to arm the weapon, Xindi-Reptilians inject their prisoner, Ensign Hoshi Sato, with neural-parasites. With the Xindi superweapon about to be armed and time running out, Captain Jonathan Archer tries to persuade the Xindi-Aquatics to help him and his Xindi allies destroy it. Sato's kidnapping, and Archer's promises to shut down the 70-plus known spheres (initially a partial, desperate bluff), finally convinces the Aquatics into believing that the Sphere Builders, and not the humans, may indeed represent their true enemy.
A battle between Archer's Xindi fleet and the Reptilian-Insectoid fleet soon breaks out around the superweapon. Locating Sato on board a Reptilian ship, a small squad of MACOs, led by Major Hayes and with the support of Lieutenant Malcolm Reed, transports on board the ship to extract her. With the space battle ongoing, the transporter system is damaged so that no more than two personnel can beam out at a time. Holding off the Reptilians on the ship, Hayes sends one of his men and Sato out first, and then the rest of the team, but just as Hayes, now alone, is beaming out, a Reptilian soldier fires through his chest. Back on board Enterprise, he tells Reed who his MACO successor should be, moments before he dies.
With the "threads of time" turning against them, the Sphere Builders decide to intervene by creating spatial distortions around the weapon. The distortions hinder Enterprise and the rest of Archer's Xindi fleet, and destroy a number of Aquatic ships, which buys the Reptilians enough time to activate the codes. Dolim (Scott MacDonald) has the superweapon enter a vortex and head for Earth, escorted by two allied ships. Inside one of the vessels, having witnessed the interference of the Guardians, the Insectoid leader begins to doubt the motives of the Reptilians. Since the Reptilians already have the Insectoids' launch code, Dolim destroys the Insectoid's ship. Far behind via the vortex, and needing to close the distance with speed, Archer takes a Xindi recommendation to pursue Dolim using Degra's faster spaceship, taking a sickened Sato with his team to guide them through the superweapon.