Season 4

October 22, 2004

Once the NX-01 finally returns to Earth, the weary crewmen face repercussions of their journeys, both positive and negative.

October 29, 2004

When genetic supermen left over from the Eugenics Wars hijack a Klingon ship, Archer must rely on their creator, the criminal Dr. Arik Soong, to help hunt them down.

November 5, 2004

Arik Soong leads his band of Augments to a medical facility where hundreds of genetically enhanced embryos are still stored, intending to retrieve them and bring them to life.

November 12, 2004

In defiance of their "father," Arik Soong's Augments devise a heinous plot against the Klingons which will surely lead to interstellar war.

November 19, 2004

Earth's embassy on Vulcan is bombed, and the ensuing investigation puts Archer and T'Pol on the trail of a Vulcan religious faction hiding in a treacherous desert.

November 26, 2004

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.

December 3, 2004

Archer, T'Pol and T'Pau attempt to bring the Kir'Shara — an artifact believed to contain Surak's original writings — to the Vulcan capital, as the NX-01 gets involved in a Vulcan-Andorian military clash.

January 14, 2005

The inventor of the transporter, Emory Erickson, comes aboard Enterprise for a risky experiment.

January 21, 2005

Non corporeal aliens study the Enterprise crew as they respond to a fatal viral infection brought on board from an away mission.

January 28, 2005

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

February 4, 2005

Archer tries to unify the Andorians, Tellarites and Vulcans in a plan to capture a marauder ship threatening to destabilize the region.

February 11, 2005

Archer visits Shran's icy homeworld to find an Andorian subspecies called the Aenar, to determine their connection to the marauder destroying ships in the region.

February 18, 2005

While Enterprise visits Earth for the launch of Columbia, Phlox is kidnapped and forced to help the Klingons deal with a grave threat toward their species.

February 25, 2005

With Columbia's help, the Enterprise crew grapples with sabotage to their ship as they pursue the truth behind the kidnapping of Phlox.

April 15, 2005

As a gift for negotiating with the Orion Syndicate, Captain Archer receives three Orion Slave Girls.

April 22, 2005

In the mirror universe, Commander Archer mutinies against Captain Forrest in order to capture a future Earth ship found in Tholian space.

April 29, 2005

In the mirror universe, Archer commandeers the 23rd-century Defiant from the Tholians and uses it in a nefarious power grab.

May 6, 2005

A xenophobic faction of humanity threatens to undermine talks to form a new coalition of planets.

May 13, 2005

A human isolationist leader threatens to destroy Starfleet Command unless all aliens leave Earth immediately.

May 13, 2005

Six years in the future, an emotional Captain Archer and the crew return to Earth to face the decommission of Enterprise and signing of the Federation charter.