Meanwhile on Qo'noS, the Klingon Chancellor and the High Council are understandably pissed (well, more pissed than usually). Twice, they've had Jonathan Archer as their captive, and twice, he's escaped. They address Duras, son of Toral, and assign him the task of finally executing him. Meanwhile, on the NX-01, the senior staff is called to the conference room. Seems Archer has been talking to Admiral Forrest three times in the last hour; something is obviously up. He finally arrives and says what happened: an alien probe has attacked Earth and a million people are dead. Enterprise has also been recalled home. He gets another call from Starfleet Command, and simply orders them to reverse course.
In the captain's ready room, Trip tries to learn from Archer what part of Florida was hit. Seems his sister still lives there, who he always protected. Solemnly, Archer says the death toll has been raised to three million, and after, T'Pol informs them that a Vulcan ship located the remains of the pod and its dead pilot. Naturally, everyone wants to know who did this and why. As if on cue, the Suliban arrive and abduct Archer. Silik brings Archer to meet Future Guy, their patron who's been manipulating Enterprise's mission and Big Bad of the series (don't worry; this is the last we ever see of Future Guy). Turns out Earth was attacked by the Xindi, a race who, like the Suliban, are pawns of another faction of the Temporal Cold War. They've been told that humans will destroy their homeworld in four hundred years, so they're going to prevent that by destroying Earth. As usual, T'Pol is highly skeptical about this "faction from the future," but Archer has little option but to believe him.
They finally arrive at Earth, and the official death toll is now seven million. As they near Sol, they are attacked by a Klingon Bird-of-Prey commanded by Duras, who quickly disables Enterprise and prepares to board her. However, he gets ambushed by Earth's home fleet and is driven off. In San Francisco, Archer tries to convince Admiral Forrest and Ambassador Soval to have him find the Xindi. While Forrest seems on board with this plan, as losing a single ship is a small price to pay if they're wrong, Soval is extremely hesitant. It seems the Xindi live in the "Delphic Expanse," a region of space home to aggressive species and unexplainable anomalies. Few ships which enter it ever return, making it a space Bermuda Triangle. Despite this, Archer plays his trump card from Future Guy: a component of the probe is actually from the future. While Forrest is able to convince Command to reassign Enterprise, Soval tries to have Archer psychologically analyzed (which naturally fails). Meanwhile, Trip and Malcolm visit Florida, seeing the vast devastation which includes his sister's house. Having not heard from her since, they naturally assume the worst.
Archer and Forrest fly to spacedock to see the NX-02, still under construction. They go over the exposition: Enterprise is getting refitted with new weapons and Archer has called on the military to send a detachment of Space Marines aboard. Despite not having a single clue about where in the Expanse to search, or even any idea when the Xindi are going to finish their weapon, Archer is confident that they wouldn't have been warned if they didn't have a chance to stop them. Meanwhile, Phlox is more than willing to stay aboard, while T'Pol is clearly conflicted about what she should do: she wants to stay, but the High Command has ordered her back to Vulcan. Down in the armory, Malcolm is overjoyed to be installing new photonic torpedoes, far more powerful than their spatial torpedoes. However, his attempts to console Trip about the death of his sister fail, with Trip merely wanting to get back at the Xindi.
In Forrest's office, Soval shows a recording from a Vulcan ship that had entered the Expanse. After being there for only two days, the entire crew became violent and killed each other. Despite this attempt to frighten Archer into not going, the humans resolve to continue. Soval attempts to recall T'Pol to Vulcan, but she believes she's needed more on Enterprise. So, with new weapons and new equipment, Enterprise departs for its new mission. While Archer and Trip have some scotch and discuss their plan, Duras attempts to ambush them again, but Malcolm's new torpedoes quickly disable him. Afterwards, T'Pol tells Archer that she's remaining on board and will resign from the High Command. With that, Enterprise makes a beeline for the Expanse.
At the vast cloud layers surrounding the expanse. Duras ambushes them again, this time with two more ships. As they approach the Expanse, his help break off and Enterprise pulls off an L-4 which allows them to hit Duras' unshielded stern, blowing him to hell and beginning his family tradition of dishonor. Archer orders a straight and steady course, taking them right into the Delphic Expanse...
- Aborted Arc: This is the first time Archer is brought face-to-face with Future Guy, the Suliban's benefactor. Naturally, such an important moment in the myth arc will not have any significance again. In fact, the Suliban themselves won't show up again until the Season 4 premiere, which finally scuttled the Temporal Cold War arc for good.
- All There in the Manual: The novelization explains what happened to Trip's sister: she was scuba diving off the coast of Cuba and was incinerated by the Xindi weapon.
- Attack Pattern Alpha: Archer has Travis perform an "L-4" to attack Duras from behind.
- Big Damn Heroes: Duras gets ambushed by Starfleet's home squadron when he first attacks Enterprise.
- Body Horror: According to Soval, a Klingon ship that entered the Expanse came back with the crew "anatomically inverted—their bodies splayed open—and they were still alive."
- Call-Back: Archer ends the episode with "Let's see what's in there," similar to Picard's last line of "Encounter at Farpoint": "Let's see what's out there."
- The Chains of Commanding: Discussed by Archer while sharing a drink with Trip.Archer: When I got this job, commanding the first warp-5 ship was about as big a responsibility as I could've imagined. Then, we began running into so many bad guys, and I had to start thinking more about the safety of 83 people.
Trip: And now the stakes have gotten a lot bigger.
Archer: Weight of the world, Trip.
- Continuity Nod: Remember those blueprints for photonic weapons that Malcolm got from the Vissians in "Cogenitor"? Starfleet was able to build them, and now Malcolm has the precursor to the photon torpedo at his fingertips.
- Cool Starship:
- The 22nd Century Klingon Bird-of-Prey makes its first appearance, and lives up to its successor's reputation of being very cool.
- Enterprise's sister ship, the not-yet-named NX-02, is seen under construction in Earth orbit.
- Dull Surprise: Hoshi looks oddly deadpan both when Archer tells his officers about the attack and when they see the aftermath.
- Eldritch Location: The Expanse is explicitly compared to the Bermuda Triangle. Supposedly it's full of hostile species and spatial anomalies.
- Explain, Explain... Oh, Crap!: When Hoshi translates the Klingons' hail.Hoshi: "Archer's an enemy of the Empire. He must be brought to justice, if honor is to be regained."
- Heroic BSoD: Trip's year-long grief over his sister begins here.
- Hero of Another Story: We finally meet another Starfleet captain: Carlos Ramirez of the Intrepid.
- Hypocrite: The Suliban's benefactor warns Archer because if the Xindi destroy Earth, it will contaminate the timeline. Even though he's been doing nothing but contaminate the timeline to his own ends. It's likely destroying Earth would impact his own existence, but he could have found a better reasoning. This is finally clarified in "Azati Prime": if the Xindi destroy Earth, The Federation will never exist and the Sphere-Builders will be unopposed when they start transforming the Milky Way in the 26th century.
- I Choose to Stay: Phlox easily makes this decision out of Undying Loyalty. T'Pol takes longer, but chooses to resign from the High Command to remain on Enterprise.
- Inspector Javert: Duras. Despite his obvious fear, he's even willing to follow Archer into the Expanse, something his wingmen are not willing to do.
- Just Following Orders: Why Dr. Forat lies his way aboard Enterprise so he can try to examine Archer's head. Phlox exposes him, and Archer orders him off Enterprise.
- Nothing Is the Same Anymore/Wham Episode: The start of the Darker and Edgier Xindi arc that takes up nearly the entirety of season 3.
- Not Me This Time: Archer immediately accuses Silik of the attack, but the Suliban has no idea what he's talking about.
- The Oner: Save for the last two seconds, the scene where Archer tells his officers about the attack is this.
- Railing Kill: An explosion in Engineering sends a Red Shirt flying.
- Shout-Out: That Apocalyptic Log from the Vaankara is right out of Event Horizon.
- Shut Up, Hannibal!: Archer gets a pretty badass line in near the end.Duras: Surrender, or be destroyed!Archer: Go to hell!
- Space Clouds: The Expanse is surrounded by "thermobaric clouds" that take six hours to traverse.
- Took a Level in Badass: Enterprise gets more powerful torpedoes, stronger hull plating, and a contingent of Space Marines, turning a ship of "peaceful exploration" into a warship.
- Villains Never Lie:Archer: Why should I believe you?
Future Guy: You have no choice but to believe me.