Season 4 poster
22 episodes

Star Trek: Enterprise - Season 4

First aired Oct 8, 2004Season 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

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Episode 1

Storm Front (1)

7.2
Oct 8, 200443 min36 votes

Archer and the NX-01 find themselves in Earth's past, with events of World War II altered by the Temporal Cold War.

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Episode 2

Storm Front (2)

6.9
Oct 15, 200443 min36 votes

With Silik's help, Archer hones in on the temporal operative who altered Earth's past and threatens to destroy all of time.

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Episode 3

Home

7.8
Oct 22, 200443 min32 votes

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

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Episode 4

Borderland (1)

7.8
Oct 29, 200443 min31 votes

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.

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Episode 5

Cold Station 12 (2)

7.7
Nov 5, 200443 min31 votes

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.

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Episode 6

The Augments (3)

7.7
Nov 12, 200443 min29 votes

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

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Episode 7

The Forge (1)

7.9
Nov 19, 200443 min30 votes

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.

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Episode 8

Awakening (2)

7.9
Nov 26, 200443 min31 votes

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.

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Episode 9

Kir'Shara (3)

7.9
Dec 3, 200443 min32 votes

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.

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Episode 10

Daedalus

6.5
Jan 14, 200543 min30 votes

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

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Episode 11

Observer Effect

7.7
Jan 21, 200543 min29 votes

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

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Episode 12

Babel One (1)

8.1
Jan 28, 200543 min31 votes

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

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Episode 13

United (2)

8.2
Feb 4, 200543 min30 votes

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

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Episode 14

The Aenar (3)

7.9
Feb 11, 200543 min31 votes

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.

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Episode 15

Affliction (1)

7.8
Feb 18, 200543 min29 votes

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.

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Episode 16

Divergence (2)

7.6
Feb 25, 200543 min30 votes

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

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Episode 17

Bound

6.3
Apr 15, 200543 min31 votes

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

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Episode 18

In a Mirror, Darkly (1)

7.7
Apr 22, 200543 min32 votes

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

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Episode 19

In a Mirror, Darkly (2)

7.6
Apr 29, 200543 min32 votes

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

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Episode 20

Demons (1)

7.5
May 6, 200543 min32 votes

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

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Episode 21

Terra Prime (2)

7.8
May 13, 200543 min31 votes

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

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Episode 22

These Are the Voyages...

6.0
May 13, 200543 min32 votes

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.