The spaceship is actually an unmanned prototype that was built at GD by Henry and Kim twenty years ago, back when they first met. Even though I always thought that Henry and Kim met in college and also didn't they always work with that Jason guy Kim ended up marrying who stole her memories? I guess he stole the continuity people's, too. Anyway, the ship disappeared seventeen years ago and has mysteriously returned with a human on board … Kim! But not the real Kim. This Kim was created by the ship's organic computer to continue its work once it realized that its systems were failing. It somehow made a human out of a single skin cell that the Original Kim left behind because she's a slob. Henry does not like this NewKim at all, and when Zane's brain fries itself when he's running a test on her, neither does anyone else. Carter suspects that NewKim tried to kill Zane, but while she denies doing it on purpose, she does acknowledge that it could have happened without her knowing. Henry's the one who realizes that Kim is not to blame, but the organic computer from the ship is -- it's spreading a virus to other organic computers (and Eureka is, of course, full of them) that can be transferred to humans. That means everyone in town will die unless a cure can be found. Kim ends up being just that, as she's the only person who isn't affected. And, of course, Carter's the one who figures out how to actually deliver the cure to the people – through plasma generators built out of townspeople's toasters, blenders, and peta-volt converters that create the immense amount of power required. After almost losing him, Jo declares her love for Zane and he returns the favor, and love is also in the air for Henry and NewKim and even Tess and Carter, who take in a meteor shower and hold hands despite their lack of chemistry.
The GD crew is out and about examining the newly-arrived spaceship. Henry is too busy smiling proudly and/or smugly to help out. Zane doesn't share Henry's good mood, accusing him of knowing all along that half the town (including Zane himself) were being forced to build the landing site for his ship. Henry denies this, saying that he had no idea the ship still existed, let alone that it could find its way back. "Who built this thing?" Carter asks, even though it's kind of clear that everyone knows the answer to this already. "I did. Twenty years ago," Henry says. Allison and Tess immediately know he's talking about "The Columbus," an unmanned prototype from GD's crazy 80s interstellar exploration days. But it was lost three years after its launch and everyone decided to just give up on it and the project, "repurposing" the facility and going in a different direction. That makes sense when you remember that as large as GD claims to be, there really only are like three lab room sets, so they need all the space they can get. Zane doesn't like it at all, but that's because, again, it turned him into a zombie. Carter asks if he should be concerned that the ship will continue to do stuff like that now that it's landed, and Henry says he doesn't think so. He also didn't think the ship would come back at all, so he kind of doesn't know much right now, does he? He says The Signal the ship sent out on its way back to Earth was supposed to be picked up by GD mission control, but since GD mission control was long gone, it simply found a way to make its own landing site. Meanwhile, should we really be launching things into space that require a freaking boson cloud exciter to land on Earth without creating a mile-deep crater? But Allison's only concern is that the ship had the gall to send them a signal that was all alien-looking and stuff. Such a tease, that ship is! Henry says that might have been the only signal the ship could send back after buffeting around the depths of space for twenty years and damaging its antenna array. Now that it's landed, Henry says, its computers have powered down and it doesn't have a mission it needs to send brain orders out to complete, so everyone should be fine. Zane still holds a grudge.
Allison pulls Henry aside with "let's check these figures," which is Carter's cue to no longer be interested in this. He talks to Tess instead, asking if she's disappointed that aliens haven't landed after all. She says the fact that the ship has information about twenty years of deep space exploration makes for a nice consolation prize. But since we now know for sure aliens aren't attacking, does she need to be around to examine it? Wasn't she only called here because of her SETI qualifications? "It's a long-term project, though. I mean, it's gonna take years to analyze all that data. Kind of blows a hole in my weekend plans," she says. Yeah, mine too. No point holding a "Tess is gone!" party now, is there? Tess says she actually did have weekend plans, albeit nerdy ones: a meteor shower. Carter says he's never seen a meteor shower, and invites her to see it with him. Nooooooo! Didn't she just say she was busy? She accepts. Noooooo! x2. Aren't there any single women in town who don't insult Carter's intelligence at every turn he can ask instead? But I do like how they're going to "go" to the meteor shower, as if it only takes place in one location and not all over the nighttime sky. Tess walks off, and Carter smiles. Nooooo! x3.