Affliction: Dr Phlox is kidnapped and forced to help the Klingons deal with a grave threat against their species. James Avery (The Fresh Prince Of Bel Air) guest stars. (S4, ep 15) [S]
The Aenar: Archer visits Shran's icy homeland to find a species called the Aenar. Are they connected to the marauding destroyer ships in the region? (S4, ep 14) [S]
United: A marauder ship threatens to destabilise the region. Archer has a plan to capture it, but it'll mean unifying the Andorians, Tellarites and Vulcans. (S4, ep 13) [S]
Daedalus: Emory Erickson, Captain Archer's mentor and the man responsible for the transporter, boards Enterprise for a risky experiment. (S4, ep 10) [S]
Kir'shara: Archer, T'Pol and T'Pau attempt to bring the Kir'Shara - an artefact believed to contain Surak's original writings - to the Vulcan capital. (S4, ep 9) [S]
Awakening: 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. (S4, ep 8) [S]
The Forge: 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. (S4, ep 7) [S]
Storm Front, Part 2: As the Nazi invasion of the US continues in an altered 1944, Archer and his crew map out their strategy to stop Vosk from building a dangerous time machine. (S4, ep 2) [S]
Storm Front, Part 1: Season four opens with the crew trapped in an alternative 1944 - the Allied forces are losing WWII and the Nazis have invaded the USA (with alien help). [S]
Zero Hour: It's showtime. Captain Archer has tried every trick in the book to thwart the Xindi plot to destroy Earth, but has it all been in vain? Dazzling series three finale. (S3, ep 24) [S]
The Council: As T'Pol and Reed go on a harrowing mission into one of the mysterious metallic Spheres, Archer and Hoshi approach the Xindi Council hoping to make peace. (S3, ep 22) [S]
Azati Prime: Archer sets off on a dangerous mission to destroy the Xindi super weapon before they can use it to eliminate Earth from the galaxy. (S3, ep 18) [S]
Doctor's Orders: The fate of Enterprise is in Dr. Phlox's hands as the rest of the crew must be induced into a coma to survive a trans-dimensional disturbance. (S3, ep 16) [S]
Stratagem: Archer finds himself face-to-face with Degra, the designer of the Xindi superweapon, and tries to trick him into revealing its location. (S3, ep 14) [S]
Proving Ground: An Andorian ship led by Commander Shran arrives in the Delphic Expanse to help Enterprise hone in on the Xindi superweapon. (S3, ep 13) [S]
Carpenter Street: Daniels tells Archer of a new Xindi plot - three reptilians have travelled back in time 150 years to 21st-century Detroit. T'Pol and Archer investigate. (S3, ep 11) [S]
Similitude: When Trip suffers a catastrophic injury, his only hope for survival is a transplant of clone tissue which Phlox grows from one of his exotic creatures. (S3, ep 10) [S]
North Star: 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. (S3, ep 9) [S]
Twilight: A spatial distortion leaves Archer unable to form any new memories. Years into the future, he wakes up and is stunned to learn the outcome of the human-Xindi conflict. (S3, ep 8) [S]
The Shipment: Archer, Reed and Major Hayes infiltrate a Xindi-Sloth industrial colony to learn more about the weapon of mass destruction that will be used against Earth. (S3, ep 7) [S]
Impulse: When Enterprise responds to a distress call from a Vulcan ship stranded in the Delphic Expanse, Archer and his boarding team are attacked by insane zombie-like Vulcans. (S3, ep 5) [S]
Rajiin: The NX-01 moves closer to a showdown with the Xindi when Captain Archer takes on an enigmatic passenger: a beautiful slave named Rajiin. (S3, ep 4) [S]
Extinction: Archer, Reed and Hoshi are on a jungle planet when they fall prey to a strange virus that turns them into primal life forms. (S3, ep 3) [S]
Anomaly: The Delphic Expanse is playing havoc with space and everything's distorted for the Enterprise crew. Plus there are predatory aliens making life very difficult indeed. (S3, ep 2) [S]
The Expanse: An alien probe launches a devastating attack on Earth. Archer, still being hunted by the Klingons, brings the Enterprise back home to investigate. (S2, ep 26) [S]
Bounty: After exploring an uninhabited planet, Captain Archer is taken prisoner by a Tellarite bounty hunter who was hired by the Klingons to return Archer to Qo'noS. (S2, ep 25) [S]
First Flight: After his close friend, A G Robinson, is killed in a mountain climbing accident, Captain Archer tells T'Pol about the Warp Two test flight almost 10 years ago. (S2, ep 24) [S]
Cogenitor: Enterprise encounters a hyper-giant star. While there, they make first contact with the Vissians - a technologically sophisticated race with three genders. (S2, ep 22) [S]
The Breach: Enterprise attempts to retrieve three Denobulan scientists from the planet Xantoras, where the Government has ordered all off-worlders to evacuate. (S2, ep 21) [S]
Horizon: Mayweather temporarily leaves Enterprise to visit the cargo ship Horizon, where he was born and raised. The Enterprise crew observes an unusual planetary event. (S2, ep 20) [S]
Judgement: After Enterprise lends aid to a group of accused rebels, Captain Archer faces a tribunal and charges of conspiring against the Klingon Empire. (S2, ep 19) [S]
Canamar: Archer and Trip are accused of smuggling and sent to the penal colony Canamar. While Enterprise negotiates their release, a mutiny breaks out on the prison ship. (S2, ep 17) [S]
Stigma: T'Pol is diagnosed with a possibly fatal neurological disease as a result of a mind meld. Meanwhile, one of Phlox's wives visits Enterprise. (S2, ep 14) [S]
Dawn: Trip's shuttlepod is shot down by a hostile race and is forced to land on a deserted moon. There, he must team up with the alien who shot him down. (S2, ep 13) [S]
The Catwalk: After receiving a warning about a radioactive storm approaching Enterprise, the crew is forced to take shelter in the ship's catwalk. (S2, ep 12) [S]
Precious Cargo: While Trip is repairing a stasis pod at a Retellian cargo ship and the woman inside wakes up, the ship is forced to make a hasty departure. (S2, ep 11) [S]