“The Expanse” is episode twenty-six of season two of Star Trek: Enterprise and the season finale.
A spherical device warps out in Earth orbit. It spins and then fires a beam at Florida, cutting an enormous trench through the state, continuing across the Caribbean and Central America. Then flies apart.
The Klingon High Council is currently annoyed with Duras, due to Captain Archer escaping a second time in the previous episode, “Bounty”. Duras was given a simple mission and Archer made a fool of him. This is his chance to regain his command and honour.
The senior staff are waiting for Captain Archer, who is speaking to Admiral Forrest for the third time in the last hour. Dr Phlox can’t remember the last time the captain asked him to join a meeting. The captain enters and tells them there’s been an attack on Earth. A probe of unknown origin fired a weapon across a swathe 4,000 km long. At least 1 million casualties. They’ve been recalled. The bridge contacts the captain; the admiral is contacting him again. Archer orders a course to Earth at warp 5.
A worried Trip arrives at the captain’s ready room. He wants to know if the admiral said which part of Florida was hit. He didn’t. Trip says she may have been away. His baby sister. Casualties are now up to 3 million. T’Pol arrives; a Vulcan transport located the probe in central Asia. It’s been retrieved and brought to Starfleet Headquarters. There was a pilot, killed on impact. Of unknown species.
On the bridge, Reed reports that Suliban ships are approaching. They don’t respond but there are Suliban on the bridge, then the lights go out. When they come on, Captain Archer has disappeared.
Silik enters where Archer is and says that someone needs to speak to him. Silik also doesn’t know anything about the attack. He repeats that someone needs to talk to Archer. With information about his species that he may find helpful. They are in great danger.
Archer is taken to see the humanoid figure from the future. He’s told that his planet was attacked by a probe sent by the Xindi, who learned their world would be destroyed by humans in 400 years. They were told by people from the future. Not the Suliban; the Suliban work for him. The probe was a test and the Xindi are building something more powerful. When complete, it will be used to destroy Earth. Another faction is involved and the Xindi were not supposed to learn about their future. This will contaminate the timeline. That must not be allowed to happen. Returned to Enterprise, the captain tells T’Pol. She is sceptical, because time travel.
Enterprise arrives back at the Solar System, where they are promptly attacked by a Bird of Prey. When they hail Enterprise and demand Archer, Archer realises it’s Duras. Enterprise is quickly crippled, but three Starfleet ships arrive and drive Duras off.
In orbit, the damage done can be seen from space. Captain Archer sees Forrest and Soval at Starfleet Headquarters; command is having a hard time buying the time travel thing and Soval states time travel is impossible. Archer says they don’t have much to lose; send Enterprise to find the Xindi. He was given coordinates. Which are in the Delphic Expanse, according to Soval. A region of space nearly 2,000 lightyears across. Only a few Vulcan ships have returned. A Klingon ship returned with its crew anatomically inverted, yet still alive. Not a nice place. Forrest says Starfleet Command needs proof. According to Archer, this response was expected.
He is taken to the probe’s debris and quantum dates the components. He shows the result of one piece to Forrest, who assumes the scanner is broken. Then the second one must be too. The quantum date is -420. In other words, from the future. Forrest is more convinced now; Soval less so.
Enterprise is in spacedock when Archer arrives in sickbay. There’s a Vulcan doctor with Phlox, Fer’at, who wants to check the captain’s exposure to radiation from the probe. During the scan, Fer’at is constantly asking about time travel. Just curious. Phlox looks suspicious and then turns around and tells Fer’at he’s finished. Fer’at is a psychiatric analyst, not a medical doctor. Phlox is annoyed and the captain isn’t happy either.
Trip’s sister is more than likely dead. There’s never going to be a body, but if she was alive, she would have contacted someone. Trip is badly affected. Enterprise is heading into the Expanse, with upgraded weapons and troops. T’Pol has to make a decision.
No cliff-hanger ending for season two, instead setting up a new arc for season three, and large time skips due to time spent returning to Earth and getting to the Expanse.