While Enterprise is surveying a black hole in a trinary star system, the stellar phenomenon causes strange effects on the crew.

Hoshi experiences her first transporter experience and strange aftereffects lead her to believe she wasn't reassembled correctly.

Trip boards an alien cargo vessel to help repair a stasis pod, which holds a beautiful woman in suspended animation. When the woman accidentally wakes up, she reveals she's not a passenger, but a prisoner.

When a lethal neutronic storm approaches faster than Enterprise can escape, the crew take shelter in the maintenance shafts inside the warp nacelles. They also provide refuge to a group of aliens, who aren't exactly honest about themselves.

During a solo test mission on Shuttlepod One, Trip is attacked by a territorial alien and forced to land on the night side of a moon. As he tries contacting Enterprise, he discovers his alien foe has made an emergency landing nearby. The two contend with each other as an extremely hot sun rises and threatens both their lives.

Enterprise visits a planet where an Interspecies Medical Exchange conference is being held. Dr. Phlox tries to obtain research on a terminal disease from the Vulcan contingency, without revealing T'Pol has been infected by it.

Both the Vulcans and the Andorians make a claim to a small planet and military conflict soon erupts. As the fighting goes on, the Vulcans announce they are willing to discuss cease fire terms. However, Imperial Guard officer Shran believes only Captain Archer can be trusted to mediate the situation, which drags the Enterprise crew into the tense situation.

The Enterprise crew find a small craft drifting in space and are surprised to find it contains a human corpse. More questions arise when the Suliban and Tholians make claims to the craft.

Archer and Tucker are arrested and placed on a prisoner transport heading for a penal colony, Canamar. They won't have a chance to correct this error, as one of the inmates plots a takeover of the ship.

Noncorporeal aliens possess the bodies of the Enterprise crew.

In a Klingon tribunal, Archer stands accused of aiding fugitives of the Empire and faces death if found guilty.

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

When militants take over a world, the Enterprise crew move to evacuate Denobulan geologists that are deep underground. Meanwhile, Phlox has to save a dying Antaran that refuses treatment due to the history of their races.

The Enterprise crew makes first contact with the Vissians, a species with three genders. Trip meets one of the species' third gender, known as Cogenitor, and learns how badly Vissians treat all Cogenitors. Trip attempts to help the Cogenitor, even though it interferes with Vissian culture.

The remnants of an alien ship and two frozen cybernetic bodies are uncovered in the arctic by a research team. These aliens soon thaw out and flee Earth, taking the research team with them. Starfleet orders Enterprise to find them, but the crew aren't prepared for just how dangerous these aliens really are.

Archer tells T'Pol the story of when he and a rival named A.G. Robinson were in competition for breaking the Warp 2 barrier.

Archer learns the Klingons have put a price on his head when he is captured by a Tellarite bounty hunter. As Enterprise pursues, a virus causes T'Pol to go into premature Pon Farr.

An alien race known as the Xindi launch an attack on Earth, causing great casualties and massive damage. As Enterprise heads back home, an unlikely source informs Archer about the Xindi and that their next attack will destroy Earth.

When a settlement of humans living a 19th-century Western lifestyle is discovered on a Delphic Expanse planet, Archer and crew set out to learn how they got there.

When Trip suffers a catastrophic injury, his only hope for survival is a transplant from a "mimetic symbiont" which Phlox grows from one of his exotic creatures.

Archer and T'Pol travel back in time to 2004 Detroit to stop a Xindi plot.

Religious zealots hijack Enterprise to use it as a weapon against the enemies of their faith.

An Andorian ship led by Commander Shran arrives in the Delphic Expanse to help Enterprise hone in on the Xindi super-weapon.

Archer finds himself face-to-face with Degra, the designer of the Xindi superweapon, and tries to get him to reveal its location.

As Archer tries to unravel the mystery of a rescued alien, long-simmering feelings explode among his senior officers.

The fate of Enterprise is in Dr. Phlox's hands as the rest of the crew must be induced into a coma in order to survive a trans-dimensional disturbance.

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

Archer sets out on a suicide mission to destroy the Xindi superweapon as Enterprise faces a brutal attack.

While dissension among Xindi ranks festers, Enterprise tries to recover from a devastating attack.

Two high-ranking Xindi offer to stop the launch of their superweapon if Archer can prove they've been manipulated. Meanwhile, the crew mourns their lost mates.

An attempt to use a Xindi subspace corridor leads the Enterprise crew to a bizarre encounter with their own descendants.

Archer and Hoshi stand before the Xindi Council as T'Pol and Reed lead a team into the heart of a Sphere.

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

Archer puts his life on the line in a risky gambit to intercept the Xindi superweapon and disarm it from within.

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.

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

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

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

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

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.

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.

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

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

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

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

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

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

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.