Even though she's a junior with a B- average, Zoe's specialness and a recommendation from Henry has gotten her into the pre-med program at Harvard a year early. Lucas takes the news even harder than Carter, and tries to get his own early admission recommendation from Henry by creating an amplifier that might be used to counteract the effects of the neutron star Nemesis, which will be swinging by our solar system in 2,000 years to reverse the magnetism of the poles -- an Extinction Level Event. The amplifier didn't appear to work, but then the new supercollider explodes when Lucas's amplifier throws off its magnetic stabilizers, thus causing a surge in electromagnetic energy and the beginnings of a new North Pole over Lucas's house. Oops! Even worse, Carter catches Lucas and Zoe making out on their way to having sex. If they can't figure out a way to dissipate the electromagnetic energy before it turns into a new pole, it will destroy us all. Fortunately, Carter, Henry and Zane figure out that they can use Martha (the drone from the first episode of the season) to shoot a burst of positive energy into the negative charges accumulating over town. But they'll have to reverse the polarity of Lucas's amplifier first, or else it'll make the problem even worse, and no one can get near the amplifier because it's in the middle of the electromagnetic field that is so strong that it can affect brain function and cause whoever is sent in there (Carter, naturally) to lose all muscle control. But wait! Tesla's biotech competition has just the solution – subcutaneous muscle controls that allow Carter's movements to be controlled from afar. It works, and the world is saved. But Carter's world is still torn apart, as not only is Zoe leaving, but Tess is also -- to a new job in Australia. She invites him to leave Eureka for good and join her there, and as the season ends he appears to be about to accept.
It's morning in Eureka, and Tess spent the night. SARAH curtly agrees to make a cup of coffee for her, having memorized her tastes "after the third night." Carter and Tess do not find this creepy, nor do they seem to realize that SARAH is probably listening to (and recording) them having sex. They make out, and Carter suggests that Tess call in sick today. She got the job, like, yesterday, Carter. It's a bit early to start slacking off. Anyway, Tess doesn't want to skip today because GD is testing a new supercollider that will no doubt wreak havoc on the town. And, Tess says, "prove the existence of dark energy." That sounds dangerous. Tess invites Carter to come watch, but he's more interested in kissing her. Zoe enters the kitchen at this point and is clearly uncomfortable with the display before her that she had a part in creating. Too late for regrets now, Zoe! Tess takes off for work, leaving Zoe and Carter to talk. Zoe says she's still in favor of Tess, especially since now she thinks that Carter won't be able to give her grief about PDAs with Lucas. Carter says he absolutely can because he's the dad, and thus gets the hypocrite pass.
So, what's in store for Zoe at school today? Well, first of all she surely has a lot of work to catch up on since she's missed so many days due to her indentured servitude at Café Diem. And second, she's participating in a diving competition for her friend Pilar's biotech final. Just what is a biotech final, you ask? Well, it's Tesla's version of school sports, and involves Pilar controlling Zoe's diving movements via a neural muscle remote of her own creation. This way, novice divers like Zoe can execute perfect dives. If it works. Which, on this show, never happens. It all sounds like a bad idea, but Carter finds it very cool and is all set to visit Tesla and watch. With that, Zoe opens an envelope and discovers that Harvard is offering her early admission to their pre-med program. Just like that! Apparently, she applied along with her classmates, and even though there are only a few spots open for students who haven't even completed their senior year of high school, they picked her. Even though she has a B- average (Zoe says that's like an A+ "in the real world") and isn't the daughter of a prominent scientist. What about all the kids whose parents went to Harvard and who have even better averages at Tesla? Why don't they get special early acceptances? Because they didn't have letters written on their behalf by a mysterious someone with a lot of pull. Zoe is thrilled. Carter is not so much. This is all happening much sooner than he expected. SARAH pipes up to inform Carter that she noticed a sudden spike in his blood pressure. Carter claims he's just excited and happy for Zoe, who runs off to tell Lucas the good news.