Enterprise has reached Azati Prime, where they find numerous Xindi starships and satellites. This confirms that they appear to have arrived at the weapon's construction site. Archer instructs the crew to hide behind a planetoid, when they detect a convoy led by Degra's ship. There, Degra toasts the imminent launching of the Xindi weapon, then the Xindi Council meet up with him. When T'Pol shares that the detection grid can't be disabled by disabling one of its thousands of satellites, Archer decides to use the Xindi-Insectoid assault shuttle, despite Travis's concerns related to their inexperience.
While Trip and Travis learn about the shuttle's controls, Hoshi attempts to learn the Xindi-Insectoid language so that she can read the information on the shuttle. Travis eventually succeeds at flying it and they find the weapon being completed underwater. Meanwhile, the moon that the Enterprise is hiding behind rotates to reveal a station, which Archer orders the destruction of lest it reveal them.
Trip and Travis come back with information on the weapon, and they find out that they can destroy it with photonic torpedoes, but that it'd kill the destroyer. Archer decides to do it, but finds himself on another ship with Daniels, who tells him that it's now the 26th century and the ship is the Enterprise-J.
Daniels reveals that in the future, the Federation will prevent the Sphere-Builders from taking over the entire Milky Way galaxy. He also reveals that the Sphere-Builders are trans-dimensional aliens, who are manipulating the Xindi into believing that humans should be annihilated. He begs Archer not to sacrifice himself, since he's going to be crucial in forming the Federation, and it wouldn't work anyway since the Xindi would build more weapons. Archer doesn't believe it and demands to be sent back, and Daniels does send him back, but has him keep an heirloom from a Xindi member of Starfleet.
Archer arrives back on the Enterprise and gives the heirloom to T'Pol. She wants to study it, but he decides to go through with his plan. She is displeased with this, since she feels Daniels's claims have merit (now believing in time travel after the events of "Carpenter Street") and also simply doesn't want Archer to die, but Archer still decides to go through with it.
Meanwhile, on Degra's ship, Dolim wants to bring more ships in after Earth is destroyed to get rid of any "residual resistance", but Degra worries that all this effort may cost them a ship. Dolim insists, then goes to investigate something he'd heard about the lunar base being out of contact, leaving Degra behind to angst over their actions.
Archer bids everyone goodbye and leaves Porthos with Phlox, then arrives at the construction site. However, the weapon is gone, and Archer is captured and interrogated by Dolim and his lackeys. At first, Archer just sasses them and doesn't answer the questions, but then he agrees to answer in Degra's presence. He has Dolim tell Degra a personal detail about his child.
Back on Enterprise, T'Pol is having trouble keeping her stoicism going, so she goes to brood in Archer's ready room. Trip tries to talk to her, but she dismisses him, then the crew determines that it's been too long without an explosion, so Archer must have been caught. Trip and Malcolm consider rushing in and destroying the weapon themselves, while T'Pol considers negotiating with the Xindi, but all of them are dubious about each other's ideas.
Archer tells Degra all the personal info he knows about him, then shows him the heirloom: an initiation medal of a Xindi who joined the Federation. Archer tells Degra that if humans are destroyed, the Xindi will be too. Degra verifies that the relic is from the future, then talks to Mallora and Jannar about ending the mission, but they think it's too late. The two Xindi-Primate councilors go to see Archer and demand more evidence, but he doesn't have any. However, he encourages them to pay attention to their doubts.
Dolim returns and, despite Degra's protests, takes Archer away for further interrogation. Four Xindi vessels open fire on the Enterprise and cause severe damage to the ship, making it seem as though all is lost.
Tropes in this episode include:
- Actor Allusion: Degra informs his fellows of what he was told about the Reptilians' actions in Detroit in the past. Mallora sarcastically asks if Archer is a time traveler.
- The Atoner: Archer volunteers for the suicide mission so that he doesn't have to order someone else to die.Travis: You're the least expendable man on Enterprise. Why are you doing this?
Archer: An hour ago, I gave the command to kill three Xindi in cold blood. A month ago, I had Phlox create a living being in order to use some of its tissue, then I watched him put it to death.
Travis: Sounds like you're saying this is some sort of penance.
Archer: I'm saying I won't order anyone else to die. - Artistic License – Biology: While being interrogated, Archer refers to mammals as the dominant "species" on Earth. Given the situation, this can be seen as an in-universe slip of the tongue.
- Berserk Button: Archer's mockery of reptiles during the interrogation gets to Dolim. He comes this close to strangling the captain.
- Call-Back:
- T'Pol is a lot less skeptical about time travel after having gone back in time with Archer. Degra later cites that episode when telling Mallora and Jannar what Archer told him.
- Dolim's General Ripper desire to eradicate all of humanity explains and closely parallels the Bad Future seen earlier in the season in "Twilight". Enterprise's crippling Curb-Stomp Battle also parallels how the ship got severely damaged in the alternate timeline, also under T'Pol's command, slowing the crew down to the point that they were unable to stop the launch of the Xindi's superweapon.
- Archer is able to get to Degra by relaying information he learned during their supposed prison break.
- Call-Forward: Daniels talks to Archer about The Federation. In addition, the ships they use at Procyon V include the Dauntless, the Prometheus, and the Nova-class, all from Star Trek: Voyager.
- Captain Crash, or rather Commander Crash: Trip accidentally bangs the Xindi shuttle into Enterprise.Trip: Sorry!
Archer: No problem. I'll send you the bill. - Cliffhanger: Enterprise tumbles through space, leaking air in a hundred places, with the Xindi still firing... Fade to Black.
- Cool Starship: The U.S.S. Enterprise-J, seen fighting the Sphere Builders in the 26th century.
- Curb-Stomp Battle: Holy crap. Four Xindi warships reduce Enterprise to a floating wreck, at the cost of one Reptilian ship.
- Darkest Hour: Archer is captured, while Enterprise takes a vicious pounding.
- Deadpan Snarker: T'Pol has some, mixed with Gallows Humor, as she goes to take a shuttlepod and work out a diplomatic solution with the Xindi.Trip: What happens if you fail? Are we supposed to just keep sending people in until there's no one left?
T'Pol: That's hardly a viable option. We only have one more shuttlepod. - Despair Event Horizon: The camera zooms in close to T'Pol's face as she watches Enterprise slowly disintegrate around her, knowing there's absolutely nothing left she can do to save her ship.
- Disconnected by Death: The Xindi are alerted to Enterprise's presence in the system because they destroyed a lunar outpost. Once it rotates back into communications range, they fail to report and so Dolim sends a patrol, which finds the ship.
- False Flag Operation: Trip and Travis use the stolen Xindi-Insectoid shuttle to fly close enough to the weapon to learn how to destroy it.
- Final Battle: Daniels takes Archer to witness one in the 26th Century, when the Federation defeated the Sphere Builders and drove them back into their transdimensional realm.
- Final Speech/Pre-Sacrifice Final Goodbye: Archer delivers one on the bridge before leaving to destroy the weapon."I've always been much better at avoiding farewells than giving them, so I'm not even going to try, but I'm going to ask all of you to think back to the day when this ship was first launched. We were explorers then. When all this is over, when Earth is safe, I want you to get back to that job. There are four hundred billion stars in our galaxy. We've only explored a tiny fraction. You have a lot of work to do. Of all the Captains who will sit in this chair, I can't imagine any of them being more proud than I am right now."
- Foreshadowing: When Jannar questions how the Reptilians traveled through time, Degra suggests "she" was responsible. We'll meet this individual in the next episode.
- General Ripper: Dolim truly begins to display this, as he tells his intentions to hunt down and eradicate "every refugee caravan, every colony, every last outpost they have."
- Get Out!: T'Pol when Trip tells her that she should be on the bridge instead of moping in the ready room.T'Pol: Dismissed.
Trip: Dismissed?
T'Pol: Get out. - Had the Silly Thing in Reverse: While learning how to fly the Xindi shuttle, Travis hits a control that makes it go backwards into the wall of the launch bay.Travis: I think I found reverse.
Trip: Great, but unless we plan to fly in ass-first, we'd better figure out how to make it go forward. - Heel–Face Turn: Degra starts to have his doubts about the cause after meeting Archer again.Mallora: We can't forget who the real enemy is!Degra: We may not know who the real enemy is.
- Honor Before Reason: Travis volunteers for the suicide mission on the grounds that he's already flown the Insectoid ship. Trip also volunteers on the grounds that he's a senior officer. Archer ends up doing them both one better.
- Humans Are Special: Daniels argues that the Federation will never exist without humanity.
- I'll Take That as a Compliment: When Archer is learning how to fly the Insectoid shuttle.Travis: Good. You're starting to think like an Insectoid.
Archer: I'll take that as a compliment. - It's a Long Story: Archer's response when Degra asks him how they know each other.
- It's All My Fault: The look on Archer's face when he learns that the Xindi are pummeling Enterprise.
- Jack Bauer Interrogation Technique: Dolim subjects Archer to this. Archer responds by taunting him about turtle soup and reptiles having walnut-sized brains.
- Lampshade Hanging: Daniels points out what had been ignored throughout this arc: if the crew manages to destroy the weapon without making peace, the Xindi will simply build another one.
- Man on Fire: One poor schmuck in engineering. Trip hoses him down with a fire extinguisher.
- New Era Speech: Degra toasts to this with his engineers."It may seem odd to celebrate the completion of a weapon, particularly one designed to destroy an entire planet, but recall the words of Enarchis written some fifty years into the Great Diaspora. 'Without a world of our own we are but children lost in the wilderness.' One day we'll emerge from this wilderness, and our work here will ensure that we'll never be lost again. To a new era for all Xindi."
- Not So Stoic: The normally stone-faced T'Pol does things like cry and shout due to her preemptive grief about Archer.
- Oh, Crap!:
- Archer, when he reaches the construction site and sees that the weapon has been moved...and some Xindi fighters are closing on him...
- T'Pol and Trip, when Malcolm contacts them over the comm:"There's no need to go to the Xindi. It appears they're coming to us."
- Dolim has one when Archer reveals he knows who Degra is.
- Archer again, when Dolim smugly informs him that Enterprise is under attack.
- O.O.C. Is Serious Business: T'Pol has a few examples this week: blurting out an emotional "I don't want you to die!" to Archer, shedding a tear in private, and Suddenly Shouting at Trip (something the engineer can't help but notice).
- Operator Incompatibility: When walking Archer through the controls of the Insectoid ship, Travis notes how hard they are to operate, and Archer suggests that they're probably made for a pilot with compound eyes.
- Race Against the Clock: Based on Trip and Travis's recon mission, the weapon is almost ready to be launched, which is why Archer feels there's no time for diplomacy.
- The Reveal: The Xindi are actually pawns of the beings who built the Spheres. The Sphere Builders have technology to see the future and know the Federation will foil their attempt to take over the galaxy, so they conspired to have the Xindi destroy Earth.
- Red Shirt: Three are seen being blown out into space when Enterprise suffers a hull breach. The next episode reveals that eighteen crew members were killed.
- Running Away to Cry: After Archer leaves Enterprise on his Suicide Mission, T'Pol retreats to the ready room right before the tears start flowing.
- Shut Up, Kirk!: Dolim responds to Archer's mockery with, "We know exactly where your ship is!"
- Space Is Noisy: Averted when Archer destroys the Xindi listening post. There's no sound from the torpedo firing to the base exploding, reinforcing the solemn tone.
- Suicide Mission: The mission to destroy the weapon—by flying into it and blowing it up—is entirely this. Trip and Travis argue over who's more expendable, until Archer volunteers himself.
- Tragic Villain: Degra admits to Jannar that he regularly tells himself I Did What I Had to Do, but he can't stop thinking about how many innocents and children will die as a result of actions meant to preserve their own race.
- Tragic Stillbirth: Degra was to have a third child (who he intended to name Trenia), but his wife got sick and suffered a miscarriage. He also says being a parent means he can't shake how his actions will kill countless children.
- Trash the Set: The bridge, engineering, and every other part of the ship take a heavy beating. And remain so for the rest of the season.
- Wham Episode: This episode reveals why the Sphere Builders are pressing the Xindi to attack humanity, sees Degra begin his Heel–Face Turn, and has the NX-01 blasted into a smoldering ruin.
- Wide-Eyed Idealist: Daniels suggests the more standard approach to solving problems in this franchise: diplomacy.
- You Have GOT to Be Kidding Me!: Trip and Malcolm's response to T'Pol's idea to negotiate with the Xindi.
- You Have to Believe Me!:
- Daniels says this when trying to convince Archer that sacrificing himself is a terrible mistake. Naturally, Archer doesn't listen.
- Archer later resorts to this when he speaks with Degra, who's highly skeptical but Archer slowly gets through to him.
