As always, spoilers for the episode and any that came before, with mild references (but theoretically no spoilers) to Stargate SG-1 from time to time. Now, on to the episode!
The team is wandering around a planet that seems to be enveloped in mist (though Rodney points out it is not actually mist as there is no humidity in the air). They went there to explore some amazing energy readings, hoping for an advanced civilization or at least a cache of ZPMs but didn't find anything but the mist. As far as Rodney is able to tell the energy readings are coming from the atmosphere itself, but he has no idea how to tap into it. Sheppard decides to call it a mission and the dial up the gate to head back to Atlantis. As the gate connects Rodney detects a massive surge in the energy readings and realizes that the gate is able to draw power from the atmosphere--enough to dial Earth.
Apparently back in the day the Ancients tweaked all of the gates in the Pegasus galaxy so that the one on Atlantis is the only one capable of dialing Earth. There is a special control crystal in the Atlantis DHD that lets it do this. McKay talks Weir into letting him take that control crystal out of the Atlantis DHD and hook it up to the DHD on the mist planet, which will allow them to dial home.
Weir and the team start to get excited about the thought of being in contact with Earth again but all agree that they wouldn't actually want to return unless they knew there was a way back to Atlantis (the ZPM that allowed Earth to dial Atlantis in the pilot was depleted by the effort). Even Teyla says she wouldn't mind visiting Earth if she knew she could come back home. They do need to make the effort to at least report back to the SGC though, because they need to let Earth know about the new threat presented by the Wraith.
McKay gets the control crystal hooked up to the offworld DHD and Weir joins the team on the mist planet to dial Earth and report. They are greeted over the radio by Walter, who tells them they can come on through. The Asgard (an advanced alien raced allied with Earth as established in SG-1) are upgrading the Earth space ship Prometheus with intergalactic capabilities. They will be able to be back in Atlantis within the month. So the whole team and Weir go through to Earth.
General Hammond is waiting for them in the gate room and debriefs them for Homeworld Command. Hammond tells them the Pentagon is very worried about the threat posed by the Wraith and thinks that at this stage of things, they should just bring home the entire expedition and cut their losses. Everyone objects to this, of course, stating that with their advanced technology, as well as their knowledge of the Ancient tech, they are one of the few, if not the only, powers in the Pegasus galaxy able to stand up to the Wraith. Also, they kind of owe it to Pegasus to help out, seeing as how they were the ones to wake up the Wraith early in the first place. Hammond tells them that Homeworld Command will consider their suggestions and sends them all off on some R&R.
Weir goes home to her boyfriend and dog, McKay goes home to veg on his couch, and Sheppard takes Teyla on a shopping spree. Everything seems to be going well, though Sheppard is uneasy, thinks that something is not quite right. Then Weir gets a call from Hammond and we next see her at McKay's place. She tells him there was an accident with the Prometheus and now they can't go back to Atlantis.
Undaunted, McKay goes to Hammond to tell him he has thought of a way to get them home. While the ZPM is pretty much depleted, it should have enough juice to get a lock on the gate of the mist planet. If it can do that, then the gate on the other planet can draw the energy from the atmosphere and do the rest of the work in opening and maintaining the wormhole. Hammond seems skeptical about the idea's chances but reluctantly agrees to let him study the ZPM. Weir meanwhile advocates trying to repair the Prometheus or asking the Asgard to borrow one of their ships, which Hammond says isn't an option at the moment. She is not willing to give up though and urges that there must be some way. We finally get to see Ford and find out he has been transferred to Antarctica, which doesn't seem to bode well for their chances of getting back to Atlantis. McKay seems oddly uncaring when Ford tells him about the transfer.
Sheppard and Teyla go to his tricked out bachelor pad. Teyla is suitably impressed, but Sheppard seems unenthused, though he is happy to find beer still in the fridge and to share it with Teyla. He is still acting a bit weird though. He comments about everyone on Atlantis and Weir and the rest of the team, wondering how they are. Teyla says she is sure they are all well.
Back at the SGC Hammond calls Weir in to tell her that McKay has figured out a way to get back to Atlantis. She asks why she wasn't informed earlier but he tells her that the mission has been reassessed. Due to the threat posed by the Wraith, they are going to be going with a more military presence, including a military leader rather than civilian, and Weir has been relieved of her duties, will not be returning to the Pegasus galaxy. Weir is surprised and upset, says she believes that the civilian aspect of the mission is still very important and believes that Major Sheppard would agree with her, to which Hammond responds that Sheppard had just dialed in a few hours ago and when apprised of the situation agreed with the switch to military leadership and that Weir should stay on Earth. Weir is understandably unhappy about this.
Back at Sheppard's place, he is still hanging out with Teyla (which makes you wonder about that comment about him "dialing in" to talk to Hammond) and he decides they should leave the apartment and go somewhere when the doorbell rings. Two of Sheppard's friends from Afghanistan are at the door, Mitch and Dex, and it is clear that Sheppard is very surprised to see them.
We see Weir and McKay at the SGC having what is very clearly two separate conversations and it starts to become clear that something in Denmark is, indeed, rotten. Weir and McKay keep flashing between their conversations--from Rodney's point of view Weir is unconcerned that his study of the ZPM seems to show that the laws of physics have stopped working, from Weir's point of view, Rodney seems not to care that Atlantis has been militarized and the scientists and civilians are being sent home. Then we start getting scenes at Sheppard's house, where a really random party has gotten underway, thrown in the mix.
Sheppard, Rodney, and Weir seem to be all coming to the conclusion that things are not what they seem at all. Sheppard reveals that Mitch and Dex died in Afghanistan, have been dead for years in fact. He is getting increasingly agitated and wants answers. Rodney knows that something is hinky because scientific fact has stopped making any sense, and no one seems at all perturbed. Weir knows that both Rodney and Sheppard would be fighting the decision about Atlantis tooth and nail. She demands the truth of Hammond when he appears behind her.
Hammond turns into a swirly ball of light and says that now she knows the truth. He reveals to her that she and her people are each in their own illusory world. Weir demands to see them and all of a sudden everyone is standing in the gate room. Hammond points out that Sheppard figured out pretty much from the start that he could manipulate the reality they had created for him (and Teyla, since she had no memories of Earth, she shared in his illusion). He says that they must each now pick their own illusion to live out the rest of their days inside. When asked why, Hammond explains that his people are the mist on the planet, an energy-based life form, and whenever the gate is activated many of their people are killed. Usually they let the sacrifices stand but they were scared when Sheppard's team left and then came back. When they looked inside their heads to find out why, they were horrified to learn of the intention to dial another galaxy, which would have killed millions of their people. To stop the team from dialing Earth, they knocked them out and put them in the fake realities.
The team manages to convince Hammond that their bodies will die very quickly in this state and they need to be let go. Mist-Hammond says he can't risk that because he can see how badly they want to go home to Earth. They promise that if they are freed they will leave and never come back. Yes, they want to go home, but they don't want to sacrifice millions of lives to accomplish that goal. In the end they are able to convince Mist-Hammond and he dissolves the illusion. They wake up on the mist planet and start packing up to go back to Atlantis.
This is the episode in which the lines start to become much more clear as to how far the expedition is willing to go in order to get back to Earth. We've seen a few nebulous tracings here and there, but here is where they start to solidify. Interestingly, we also start to see the core of the expedition realize that they don't actually want to leave the Pegasus galaxy. As much as they want to get back to Earth and the people and lives they left there, they also have a lot to do in Atlantis, and if the choice is leave for good or stay forever, they are staying. The title of this episode, "Home," is especially apt. As it begins, "home" is very definitely Earth to everyone but Teyla (for whom "home" is Athos). By the end, however, they have come to realize that this is no longer the case. Atlantis has become home to all of them, whether they intended for it to do so or not. This small fact, established so casually in this episode, becomes a core aspect of the series as it progresses. But here is where it is well and truly introduced.
There is also some good character development in this episode. At this point Weir and Sheppard's team are the five leads of the show, and we get to see a little bit more of the private lives of each of them (except for Ford, oddly enough, though we do hear that he spent his time on "Earth" with his grandparents). We see Weir's feelings of guilt for leaving Simon behind, which does not dim her belief in what she is doing one bit. We find out that Sheppard brought along a copy of War and Peace to Atlantis because he figured they would be there for a while and wanted to take a book that took a long time to read (he is on page seventeen, which is right on schedule according to him). We also learn that he likes Johnny Cash and get some of his pre-Atlantis background. Rodney has a cat that his cute brunette neighbor is watching for him while he is away. Teyla enjoys a good shopping spree. Also, she acknowledges the wasted potential of her people. She wonders what kind of civilization the Athosians might have created had it not been for the Wraith.
We learn that each and every one of them feels that their place is in Atlantis, fighting the Wraith and doing all that they can to learn about the Ancients.
It's actually a very interesting episode given how little action there is. It is not the ordinary Atlantis fare--there is a life or death situation but it is handled swiftly and never a real threat to our people. I like how there are many clues scattered throughout the episode for the audience that things are not what they seem. There are the obvious bits of course, like how Weir and Rodney had their outfits change according to which perspective we were seeing. Also the fact that even though these people have been away for weeks, at least, possibly months, everything is more or less just how they left it (including cheetos in the couch even). But there are also some more subtle clues scattered in there as well, that I am only now picking up after multiple viewings. Like Hammond's mention that Sheppard had dialed in to the SGC when as far as we can tell, he has been wandering around with Teyla this whole time. It's one of those things that rewards you for paying attention, and I like that every now and again.
"So what you're saying is, you're invaluable everywhere?" (Ford to Rodney)
"Well you wouldn't know it from this, would you? This might as well say bing tiddle tiddle bong! I mean, it's complete gibberish!" (Rodney)
"I'm not a scientist, Rodney." (Weir)
"Well neither is anyone else around here apparently, otherwise they would have noticed the laws of physics seem to have flown out the window." (Rodney)
"What happened?" (Sheppard)
"I drew you together from your fractured realities." (Mist Hammond)
"I'm talking about the beer I had." (Sheppard)
"Cute brunette. I should have known! How do you go from 'You're a pig, but I like your cat.' to 'I missed you!'?" (Rodney)
"The dead people were a dead giveaway." (Sheppard)
That's all I've got for today, folks. See you back here on Wednesday for "The Storm." That's when stuff starts getting really intense.