Star Trek: Enterprise — Season 4
Upon returning home after preventing a second Xindi attack, Enterprise explores cultural shifts on Vulcan; forges alliances with Earth's neighbors in the face of Romulan aggression; deals with a plague inside the Klingon Empire; explores the Mirror Universe; and overcomes xenophobic elements to lead an interstellar community.
Episodes

E01 Storm Front (1)
★ 7.2Oct 8, 2004 · 43m
Archer and the NX-01 find themselves in Earth's past, with events of World War II altered by the Temporal Cold War.

E02 Storm Front (2)
★ 6.9Oct 15, 2004 · 43m
With Silik's help, Archer hones in on the temporal operative who altered Earth's past and threatens to destroy all of time.

E03 Home
★ 7.8Oct 22, 2004 · 43m
Once the NX-01 finally returns to Earth, the weary crewmen face repercussions of their journeys, both positive and negative.

E04 Borderland (1)
★ 7.8Oct 29, 2004 · 43m
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.

E05 Cold Station 12 (2)
★ 7.7Nov 5, 2004 · 43m
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.

E06 The Augments (3)
★ 7.7Nov 12, 2004 · 43m
In defiance of their "father," Arik Soong's Augments devise a heinous plot against the Klingons which will surely lead to interstellar war.

E07 The Forge (1)
★ 7.9Nov 19, 2004 · 43m
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.

E08 Awakening (2)
★ 7.9Nov 26, 2004 · 43m
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.

E09 Kir'Shara (3)
★ 7.9Dec 3, 2004 · 43m
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.

E10 Daedalus
★ 6.5Jan 14, 2005 · 43m
The inventor of the transporter, Emory Erickson, comes aboard Enterprise for a risky experiment.

E11 Observer Effect
★ 7.7Jan 21, 2005 · 43m
Non corporeal aliens study the Enterprise crew as they respond to a fatal viral infection brought on board from an away mission.

E12 Babel One (1)
★ 8.1Jan 28, 2005 · 43m
Enterprise journeys to Babel with a Tellarite ambassador on board for peace talks with the Andorians, when a distress call from Shran is received.

E13 United (2)
★ 8.2Feb 4, 2005 · 43m
Archer tries to unify the Andorians, Tellarites and Vulcans in a plan to capture a marauder ship threatening to destabilize the region.

E14 The Aenar (3)
★ 7.9Feb 11, 2005 · 43m
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.

E15 Affliction (1)
★ 7.8Feb 18, 2005 · 43m
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.

E16 Divergence (2)
★ 7.6Feb 25, 2005 · 43m
With Columbia's help, the Enterprise crew grapples with sabotage to their ship as they pursue the truth behind the kidnapping of Phlox.

E17 Bound
★ 6.3Apr 15, 2005 · 43m
As a gift for negotiating with the Orion Syndicate, Captain Archer receives three Orion Slave Girls.

E18 In a Mirror, Darkly (1)
★ 7.7Apr 22, 2005 · 43m
In the mirror universe, Commander Archer mutinies against Captain Forrest in order to capture a future Earth ship found in Tholian space.

E19 In a Mirror, Darkly (2)
★ 7.5Apr 29, 2005 · 43m
In the mirror universe, Archer commandeers the 23rd-century Defiant from the Tholians and uses it in a nefarious power grab.

E20 Demons (1)
★ 7.5May 6, 2005 · 43m
A xenophobic faction of humanity threatens to undermine talks to form a new coalition of planets.

E21 Terra Prime (2)
★ 7.7May 13, 2005 · 43m
A human isolationist leader threatens to destroy Starfleet Command unless all aliens leave Earth immediately.

E22 These Are the Voyages...
★ 6.0May 13, 2005 · 43m
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.


