In the mess hall, Trip is showing Phlox and T'Pol some drawings drawn by his nephew (who's in the fourth grade) and the nephew's classmates. Then, Archer calls everybody to the bridge because he's discovered a comet (the largest ever seen by a human or a Vulcan) and wants to follow it. That night, Trip and T'Pol have a little talk in the mess hall while she reads and drinks tea and he eats pecan pie.
The next day, she notes that the comet contains a rare, elusive mineral called "eisillium". Noting that the deposits are too deep for the transporter, she prepares Malcolm and Travis for a landing in a shuttlepod. A Vulcan ship called Ti'Mur appears and hails the Enterprise, wanting to observe what the crew are doing. Archer agrees in the interest of cooperation, but is unhappy at the idea of the Vulcans "looking over their shoulders".
Malcolm and Travis land on the comet and start their scans. Meanwhile, Trip grows suspicious after discovering that T'Pol has received coded messages from the Vulcan ship. He tells Archer, who gets angry and has Hoshi decrypt it. On the bridge, the crew answer several questions from Irish schoolkids, including what happens when you flush a toilet (much to Trip's embarrassment), how they talk to aliens, and whether germs can survive in space.
Malcolm and Travis set up their equipment on the comet, while Travis builds a snowman. Back on the ship, Hoshi hands Trip the message, which she decrypted but didn't read as she thought that'd be rude. Trip translates it with the ship's translation matrix and it turns out to be a personal note relating to her arranged marriage. This embarrasses Trip, who feels he must tell T'Pol. He does, and apologises profusely, but she is still displeased.
Archer calls T'Pol over to discuss inviting the Vulcan captain, Vanik, over to dinner to establish trust between the two species. She then goes to see Phlox about some insomnia, who gives her an analgesic. Meanwhile, on the comet, Malcolm and Travis add pointy ears to the snowman and then Malcolm blows it up.
At dinner, Archer talks to Vanik about various things such as his ship, but Vanik is cold and laconic. Archer notes that he's suspicious that Vulcans keep cropping up yet apparently don't explore and accuses Vanik of spying on Enterprise. Archer then notes that the explosion on the comet changed its course towards the star, thus heating it up. Malcolm and Travis promise to leave.
T'Pol then talks about her arranged marriage to Trip in private, revealing a problem: if she does get married, she'll have to leave for at least a year. Trip gets very angry, since he thinks arranged marriages are unethical, which offends T'Pol and she accuses him of being culturally insensitive.
On the comet, Travis injures his leg, forcing Malcolm to help him walk. They hurry to the shuttlepod with the core sample, but when they get to the shuttlepod, it isn't working, and they fall through the surface. Vanik wants to help, but Archer refuses and tries to have Trip use the grappler instead. However, it doesn't work, so T'Pol convinces Archer to swallow his pride and accept Vanik's help, pointing out that doing so would help Vanik see past his prejudices against humans. Vanik rescues Malcolm and Travis with his tractor beam (which Starfleet doesn't have yet) but refuses the data they collected. Meanwhile, T'Pol decides to reconsider her arranged marriage.
Tropes
- Ain't Too Proud to Beg: Archer visibly resists the urge to play this trope straight when Malcolm and Travis are in trouble and only the Vulcans can save them. After deliberation, however, he gives in.
- Alliterative Name: The girl who asks the "poop question" is named Molly McCook.
- Arranged Marriage: The first time T'Pol's betrothal to Koss comes up. It won't be the last.
- Artistic License – Physics: The comet is said to have a diameter of 82.6 kilometers, yet when Reed and Mayweather land on its surface, it inexplicably has a gravity equivalent to Earth. In real life, the gravity on such a small object would be extremely weak, but the plot requires it to be stronger to add drama to the away team's mission by having them fall through the ice.
- Bait-and-Switch: After Archer tells Trip to have Hoshi make decrypting the transmission her top priority, the scene cuts to the three of them on the bridge, with Hoshi asking Archer if they should go through with it, and he says yes. They then start a reply to one of the schools that sent them letters and pictures.
- Career vs. Man: T'Pol has to choose between staying on Enterprise or returning to Vulcan to marry Kos. She insists to Trip that she must do the latter as per Vulcan tradition, but Trip suggests that she's subconsciously leaning towards the former.
- Continuity Nod: Travis mentions only having seen snow twice in his life. Well, we remember one of those times.
- Defrosting Ice Queen: T'Pol asking Trip for advice on how to proceed with the marriage is the first step in her long trip towards better relations with her human crewmates.
- Distressed Dude: Malcolm and Travis end up sinking under the surface of the comet and needing rescue.
- Double-Meaning Title: Literally breaking the ice on the comet and figuratively breaking the ice between Trip and T'Pol (and humans in general and Vulcans in general).
- Honor Before Reason: Why Trip admits to T'Pol that he read her letter. There's no logical reason to do so, but his own conscience won't let it go.
- Ironic Echo: T'Pol repeats "You are human; you are free to choose." back to Archer when he's having trouble deciding whether to swallow his pride and ask the Vulcans to help them rescue Travis and Malcolm.
- Jerkass: The Vulcan captain is at best condescending to Archer, and at times openly rude.
- MacGuffin: The eisilium in the comet. It's very rare, so Archer seizes the chance to mine some of it. Too bad it's never explained what eisilium is used for.
- Nobody Poops: It appears they do, with the result recycled as boots and other useful items. No wonder Klaang was complaining about "stinky boots"!
- Oh, Crap!: Played for Laughs— Trip's face crumbles when Archer tells him to answer a question about where the poop goes on a starship.
- Secret-Keeper: Since Trip already read her letter, T'Pol decides to confide in him regarding her Arranged Marriage.
- Serious Business: The message about T'Pol's marriage is encrypted for privacy reasons, but as Archer is already suspicious of the Vulcans he has Hoshi decode it. Trip complains that all the Vulcans had to do was label it "Personal" and it would've been left alone.
- Snowball Fight: Travis suggests having one on the comet, until Malcolm points out that EV suits they're wearing would defeat the point.
- Space Is Noisy: That was a very nice, loud explosion on that comet, Malcolm.
- Take Our Word for It: T'Pol describes a child's drawing of Enterprise as "crude, but surprisingly accurate". Too bad Trip doesn't angle it for the viewers at home.
- Toilet Humour: One gag involves Trip being embarrassed to answer a "poop question" when asked where it goes when you flush the toilet on the Enterprise.
- What the Hell, Hero?: T'Pol chews Trip out for reading a letter addressed to her. Of course, he's already beaten himself up over it.
- You Have GOT to Be Kidding Me!: Trip's reaction to having to answer a question about what happens when a toilet is flushed.
