Leila is in an Airborne Infection Isolation Room, which is just the latest version of the clean rooms this show loves. Sean tells her they're working on a way to help her. Although they don't know how to cure regular flu in 100% humans, so I'm not sure how far they're going to get when they have only a few hours to cure Superflu in a human-alien hybrid. I wonder what happened to Doctor Lu. Now that the virus plan is off, maybe she'd be willing to help out with this. Sean, of course, is confident they'll find a way to cure her. Anyway, it's time for the Shocking Revelation. Leila tells Sean that she's pregnant. First of all, that's the most obvious plot twist ever. Second, shouldn't Doctor Lu have noticed that? Sheesh. And is this what's going to lead to The Event? Because that's interesting if it's the first human-alien hybrid, but there are apparently a bunch of those already. The first three-quarter-human-one-quarter-alien doesn't make for a great prophecy. Anyway, Sean and Leila say they love each other, and with that, we leave them. Forever. Hooray!
We get a couple of helicopter shots to establish that we're returning to the White House. They artfully avoid showing the Washington Monument, and I was so hoping to catch the producers in one last continuity error.
Sophia is brought into the Oval Office. Martinez tells her they've identified the portal array in Tibet. Simon adds that he's told them everything he knows about the portal. She says that they can't stop the portal, and also that she won't tell them where the landing site is. Then she attempts to scare everyone by saying that the virus was supposed to be an act of mercy. Now that the aliens are coming through anyway, "The only choice open to us will be far from humane." Then the camera joggles a little and Sophia announces, "It's too late."
A portal opens up in space. Wind picks up on a variety of streets. Vicky looks at the sky. Leila and Sean look around. Sean sees a light out the window. The Oval Office crew goes into the Rose Garden. Sophia is smiling. Christina holds her son. This is taking forever. Finally, the entire alien planet appears in the sky over Washington, DC. It looks like it's closer to Earth than the Moon is. One of the Martinez children runs to Christina and asks what it is. Christina's answer: "Home."
And that's how it ends. First of all, I want to point out that I was right about Christina being an alien. So, you know. Good for me.
Second, they brought the entire planet over. So why did they try to kill all the people on Earth? They have their own planet. The only problem with the planet was that it was getting irradiated by their sun, so as soon as it was parked in front of our lovely yellow sun, everything should be fine. I mean, now that the two planets are right next to each other, they'll probably crash into each other or something, but that, again, is just bad planning. Here's what you do: you look up Lagrangian Point. See? There are gravitationally stable points that you can drop a whole alien planet into and not cause all these earthquakes. Then the aliens can be on their planet, and the humans can be on Earth, and nobody's got a problem.