When Enterprise is attacked by an unidentified enemy ship, the crew must work frantically to get their new phase canons to operate. Meanwhile, the captain charges Hoshi with finding out Malcolm's favorite food in time for a surprise birthday dinner.

Archer and Reed return to a pre-warp society, that is on the verge of war, to recover a lost communicator from an undercover survey mission.

Mayweather discovers his father has died and that things on his old home, the E.C.S. Horizon, have greatly changed.

On a mission to investigate an abandoned Xindi vessel on a jungle planet, Archer, Reed and Hoshi succumb to a virus that mutates them into a primal life form.

Archer goes to extreme lengths to save an abandoned nest of Xindi-Insectoid eggs ready to hatch.

With help from Xindi allies, the Enterprise crew attempts to stop the arming of the Weapon aimed toward Earth.

Archer and T'Pol encounter the Syrrannites, a radical group hiding in the Vulcan desert, while the NX-01 crew contends with Vulcan power ploys.

Enterprise journeys to Babel with a Tellarite ambassador on board for peace talks with the Andorians, when a distress call from Shran is received.