The Connors are finally moving out of the Compound and heading for a safe house, only Sarah's taking John on a detour without Cameron and Derek because she doesn't trust either of them anymore. They head to a house on the water, by a lighthouse, which is where Charley's hanging out, and doing supportive things like rigging the place with Semtex in case everyone needs to make a quick getaway by boat. Sarah wants Charley to feel her breast, but not in that way (especially since he's still grieving the loss of his wife). She's found a lump, and she's worried that the cancer she was originally supposed to die of in 2005 has finally caught up with her.
So she goes to the doctor, where she founds out that the lump isn't a tumor but a cystic mass that's gathered around a little piece of metal. She figures out it’s a tiny transmitter, and Sarah uses a defibrillator to zap it (and herself) out of commission, but the shadowy dudes are already converging on her location.
Cameron and Derek are also in trouble, both from each other -- Derek gets upset when Cameron breaks the news to him that Jesse was pregnant with his child aboard the Jimmy Carter and lost it -- and from the shadowy bad guys. They manage to kidnap Derek, but Cameron tracks them down and rescues him. Sarah defibrillates a bad guy's head and escapes and heads back to the lighthouse, where she arrives after a firefight and explosion. John's nowhere to be found. Charley's there, though. Only he's floating face-up in the water.
Meanwhile, John Henry's making real progress. He goes from playing with Lego to Savannah to being the target of an artificial intelligence trying to get inside him with a worm to control him remotely. He recognizes some of the computer code within the other intelligence, since he's got the same stuff. This other intelligence is more advanced, but it's like they're brothers, and their father is Miles Dyson.
So the "Previously On" scenes go all the way back to the beginning of the series, and feature Charley pretty heavily. Which really can only mean one thing: hasta la vista, Charley.
So Sarah's still packing up as the family is almost ready to leave the Connor Compound, but not before Sarah reminisces about John growing up in the jungle, which means a flashback to the cheesy "jungle" set this show likes to use, and she tells us that the jungle stories were John's fairytales, and his favorite was about El Viejo Del Monte, which, if my Spanish isn't completely off, translates as "the old man of the canned peas," and this guy was a merciless killer who didn't leave any animals alive wherever he went. But he didn't eat his prey, just left it behind to rot in the earth. To teach him a lesson, the gods turned him into a simisco, a half-animal, half-man, and condemned him to guard the jungle for all eternity. Is this a real myth? Or one tailored to sound very applicable to John? Did the gods send someone back from the future to protect El Viejo too? Anyway El Viejo's punishment is to keep vigilant forever.
Meanwhile, the boyish John (who looks like he just had his hair cut at Supercuts or some shit instead of being all dirty and smelly and jungle-esque) is calling to Sarah (who has kept her looks all these years, as she looks exactly the same, but at least they didn't use the Sopranos put-a-baseball-hat-on-her-in-flashbacks-to-make-her-look-younger Christopher Moltisanti technique), because he's spotted a red parrot in the branches, and I can see why John would love a story about a merciless aniimal-killer so much, only Sarah is all crabby and tells him they need to keep going, because it's part of the game. "You mean 'training,'" says John, and Sarah says if she calls it a game, it doesn't seem like so much work, and John looks like he heartily disagrees with that theory. This is worse than your Scrub The Outhouse game! "The point is, to listen to me," she says. He tells her that he always listens: "You don't talk that much."
Back in the present day, John tells Sarah that they gotta go, and so they clear out, Cameron carrying a box out the front door past Derek walking in. Sarah asks how long it will take him to pack up the storage locker. "A while. Some explosives that need securing," he tells her. She tells him to get to the safe house before dark, and not to get lost, and he tells her he can follow directions, and she says, "You can also make mistakes," only this time she hopes no one gets KILLED because of them, because Sarah is perfect and doesn't make mistakes, and Derek's a little too stunned to respond, and Cameron fills the silence by giving him the coordinates, which she says is in the desert. "Things happen out there," says Sarah. "Things happen here, too," says Cameron, and John comes strolling in to decree that whatever happened in the house stays in the house, and that they're starting over.