Hoshi wakes up on the Xindi ship she was beamed to in the last episode. It turns out that Dolim, who knows that she speaks Aquatic, wants her to translate some Aquatic launch codes. Meanwhile, the away team returns with some information, which T'Pol orders Trip to incorporate into the ship, and the rest of the team are informed of what happened while they were away. Most of them leave, then Malcolm tells Hayes what happened to Hawkins.
Archer meets on the Xindi council planet with the primate councilor and Jannar, who tell him that they're looking for the weapon, which needs three more codes in order to activate, and so the Reptillians and Insectoids are probably going to try to hack into the command sequences. T'Pol and Trip work on the sphere data, then they tell Archer that they believe four of the spheres control an energy grid, which controls the remaining spheres, thereby allowing them to take down all of them if there's a weak point.
Meanwhile, Dolim has injected Hoshi with neural parasites to try to force her to cooperate, and Archer, Jannar, and the Primate councilor have found the weapon but it's being guarded by four more ships. Archer convinces Kiaphet Amman'sor to meet with him to discuss getting help from her and the other Aquatics, and she initially feels that intervening is too "rash", but he points out that if their homeworld they're trying to protect is in the Delphic Expanse, the anomalies will eventually render it inhospitable anyway. The Aquatics almost leave, but decide to stay when Archer tells them he knows how to destroy the spheres.
Hoshi, affected by the parasites, is now working, but when Dolim tries to inject her again, she runs away. However, a Reptillian catches her, then the guard finds out that Hoshi actually added another layer of encryption. Meanwhile, Trip and even T'Pol are getting antsy while trying to work.
The female Sphere-Builder contacts Dolim and is glad that they've reached the weapon but disappointed that they're having trouble activating it. Dolim asks her why she can't just look back in time and get the codes herself, but she reveals that she can only look back if there's been a large change in the timeline. She then hurries him up as apparently other timelines favour other Xindi species and humans.
T'Pol and Trip tell Archer that they initially planned on using the deflector dish to do the damage, but they haven't quite planned it out yet. Archer invites the Primate councilor on board, who reveals that the Aquatics are very deliberate, which is partly why they were hired to build the weapon. Then, Archer and the Primate councilor learn that the Aquatics have sent six ships, and Amman'sor hails them, agreeing to help as long as Archer helps her.
Worried about these new developments, the Sphere Builders unlock the weapon's computer systems and give the Reptilians access to begin its activation. The crew of Enterprise ready the ship for battle as the Allied armada moves out. While Hayes plans to rescue Hoshi, Malcolm arrives and they have a conversation about Hawkins's death. Later, Archer, T'Pol, and Trip talk over dinner about what they'll do once the mission is over.
They reach the weapon and the Enterprise and her allied ships begin fighting with Dolim and his people. T'Pol finds where Hoshi is, so Archer orders Hayes, Kelly, Money, and Richards beamed there. They find an unconscious Hoshi and carry her to the beam-in point. The Sphere-Builders fight back by generating more anomalies, which destroys several ships and breaks the Enterprise's transporter. Trip fixes it, but can only beam two at a time, with Money being seriously injured from being shot. Archer tries to steer Enterprise closer to the weapon, only to get sucked into a vortex to Earth, along with a Reptillian and an Insectoid ship.
Malcolm visits Hayes in sickbay and thanks him for saving Hoshi, but Hayes dies due to a heart injury. Meanwhile, Jannar and the Primate councilor tell Archer that the weapon will reach Earth in ten hours. The Aquatics won't be able to reach it in time, and Degra's ship isn't powerful enough. Archer tries to board the weapon and destroy it from the inside, then, he orders T'Pol to go ahead with her plan.
Malcolm tells the other MACOs about Hayes's death and Archer's plan, then chooses Woods, Forbes, and Romero for his mission and tells them to meet him at the airlock in ten minutes. Archer asks Phlox about Hoshi and Phlox reveals that she's better, but not fully recovered. Archer tells Phlox to have her ready within the next twenty minutes, and to teach Malcolm how to continue her treatment. Phlox wonders why he can't just do the treatment himself, but Archer believes Phlox is needed on Enterprise.
In the vortex, the Insectoid captain contacts Dolim, angrily realising that, due to the appearance of the anomalies, Archer may be right about the Guardians building the spheres. Dolim then has the Insectoid ship destroyed, while Archer, Malcolm, the MACOs, and the still-sickly Hoshi leave.
Tropes in this episode include:
- Action Film, Quiet Drama Scene: Episode, rather. Archer, Trip, and T'Pol having dinner before the battle. Also, Malcolm and Hayes discussing the upcoming rescue mission for Hoshi.
- All a Part of the Job: Hayes' response to Malcolm thanking him for rescuing Hoshi: "All in a day's work."
- Awakening the Sleeping Giant: It's made clear that the Aquatics are the most powerful Xindi species, but also the least likely to get involved in conflicts. When Archer does persuade them to help, it greatly turns the tide against the Reptilians and Insectoids.
- Big Badass Battle Sequence: Two opposing Xindi fleets fighting over the weapon.
- Call-Forward: T'Pol discusses the possibility of formalizing her role in Starfleet, so Trip muses about a Vulcan wearing a Starfleet uniform and Soval's possible reaction. (Also a Callback to "Twilight" in which T'Pol did wear a Starfleet uniform. Soval was not impressed.)
- Cool Spaceship: The Aquatic spaceships, which resemble giant manta rays.
- Damsel in Distress: Hoshi is captured by the Reptillians so they can force her to crack the launch codes.
- Divine Intervention: Right as the Reptilians and Insectoids are on the cusp of losing the battle for the weapon, one of the spheres activates and begins to disable multiple allied ships. Dolim interprets this as "The Guardians will not let us fail."
- Even Evil Has Standards: Dolim briefly calls out the Guardians for splitting the Xindi into a civil war in order to launch the weapon.
- God's Hands Are Tied: The Sphere Builder claims they're unable to help the Reptilians arm the weapon. However, once Archer manages to unite the other species, they immediately unlock the weapon's computer. They also create new anomalies to disable the allied fleet and allow Dolim to slip away with the weapon.
- Heel–Face Door-Slam: After a cluster of anomalies intervenes in the battle on their behalf, the Insectoid Councilor realizes that Archer has been telling the truth the whole time: that the "Guardians" are indeed the Sphere-Builders, and the Xindi's true enemy. However, when they attempt to voice their doubts to Dolim, the Reptilian simply has his erstwhile ally shot down.
- Hyperspeed Ambush: The attack on the weapon. Enterprise hitches a ride in the Aquatics' flagship.
- Ignored Epiphany: Dolim also figures out the truth about the Guardians, but it doesn't dissuade him one bit.
- Indy Ploy: Archer attempts to reason with the Aquatics to gain their help. When they remain committed to waiting, Archer goes for the Hail Mary: he makes a big promise about shutting down the Spheres.
- Irony: To go after the weapon, Archer must use the ship that belonged to the man who designed it.
- Jumped at the Call: After reporting the news of Hayes's death to the MACOs, Reed says they're preparing a mission to destroy the Xindi weapon and that he needs three volunteers. Every MACO there steps forward.
- Kick the Dog: Dolim mocks Hoshi before the real work begins."Before your primate brain is too badly damaged to understand, I want to thank you for helping us destroy your world."
- Lock-and-Load Montage: On Enterprise before the battle, while Archer records his Captain's Log.Captain's Starlog, February 13th, 2154. We're preparing to enter a Xindi vortex, thanks to some help from the Aquatics. If everything goes as planned, we'll intercept the weapon in less than two hours. Enterprise may be coming apart at the seams, but I can't say the same for the crew. After nearly eight months in the Expanse they're ready to do what they came to do. No matter what it takes, no matter what the cost.
- Mighty Glacier: The Aquatic flagship is the most powerful Xindi warship, but it's also the slowest.
- Negated Moment of Awesome: As the Xindi weapon powers up its vortex drive, Archer orders Travis to fly in close for an attack. However, with all the anomalies and fighting ships around, the NX-01 is unable to reach the weapon in time.
- Neutrality Backlash: Archer tells the Aquatics that if they don't take action instead of endlessly deliberating, the Reptilians and Insectoids will make further deliberation moot.
- No OSHA Compliance: The interior of the weapon has lots of narrow walkways above deep chasms, and very few handrails.
- Oh, Crap!: Dolim, when he realizes that the Aquatics are incoming and then when Enterprise joins the fray.
- O.O.C. Is Serious Business: Considering the Aquatics once took six days to agree to attend a council meeting about a simple logistical matter, Mallora is astonished that they made a decision in only three hours.
- Puppeteer Parasite: The Reptilians inject Hoshi with them to force her to cooperate.
- Rousing Speech: Malcolm gives one to the MACOs.Malcolm: I've just come from Sickbay, where the Doctor assures me that Sergeant Kemper and Ensign Sato will make full recoveries. Unfortunately, Major Hayes' injuries were more severe. He didn't survive. I'm sorry. We've got less than ten hours before this weapon reaches Earth. The Captain wants to take a team aboard to destroy it. I don't imagine the Reptilians will make this easy for us, but that's why you're here. That's why Major Hayes picked each one of you for this mission. Because he knew you'd get the job done.
- Sacrificial Lion: Alas, poor Hayes...
- Spiteful Spit: Hoshi's response to Dolim's threats.
- Took a Level in Badass: Not only is Hoshi able to resist the initial injections, but she's able to stall the Reptilians by adding an additional layer of security.
- Tranquil Fury:Archer: Feel like taking [the Xindi] on?
Malcolm: Give me the word, sir. - Two-Keyed Lock: Each of the five Xindi species has its own set of codes; at least three out of the five are needed to control the weapon. The Reptilians and Insectoids only have two, so they force Hoshi to decode a third set.
- Why Did It Have to Be Snakes?: Jannar is visibly uncomfortable while waiting aboard the Aquatic flagship because Arboreals don't like water.
- You Are a Credit to Your Race: One of Dolim's minions describes Hoshi as "surprisingly strong-willed - for a primate".
- You Called Me "X"; It Must Be Serious: T'Pol calls Trip by his nickname for the first time, so she can apologize for being out of sorts.
- You Have Outlived Your Usefulness: When the Insectoid councilor begins to wonder whether Archer was right, Dolim thanks him for their launch code and fires on their ship. Not even the Insectoids will be able to rule in Dolim's new empire.
