We open with Island Ben running away from Smokey's Temple Massacre. He runs into Miles, Frank, Sun, and That Chick. That Chick hands Jacob's ashes over to Miles, and it's enough for him to pick up on something -- that Ben killed Jacob. This pisses off That Chick and she makes Ben dig his own grave.
Locke shows up and asks what Ben's doing. Gotta love his Classic Ben delivery of: "I'm digging my own grave." Locke helps him escape and tells him to meet him on the Other Island, the Hydra Station. Ben has a tearful moment with That Chick where he apologizes and says he understands because he watched his daughter Alex die. She decides all is cool and says Ben can come with her instead of Locke.
Ben chooses to stay on the Island with That Chick and the Gang.
Non-Island Ben is teaching history and has a bad haircut. Arzt is a teacher there too, natch. And Locke, who you'll recall is substitute teaching, encourages Ben to lead an uprising against the Principal he hates. Ben is also taking care of his sick father. His dad informs the audience that they signed up for the Dharma Initiative, went to The Island, but didn't stay.
Alex is here too, but she's not Ben's daughter, she's a student. A student who knows his home address and shows up to it. CREEPY. While they're studying, Alex tells Ben how she once caught the Principal and the School Nurse doing it. CREEPIER. Ben asks Arzt to hack into the Nurse's email account. Even though Arzt is a chemistry teacher. Sure, I'll go with it - science nerds can do everything.
So Ben lucks into sexy emails and blackmails the Principal with them. He tells him to resign and recommend Ben as his replacement. The Principal counters: if you make me quit, then I will ruin Alex's future and not recommend her to Yale. Wow, this Principal is a real asshole. Seriously. Dick.
Ben chooses his life of misery as a history teacher, but at least Alex is happy.
Also on the Island, Hurley and Jack meet up with Richard in the jungle. He tells them everyone in the Temple is dead and he leads them to the Black Rock ship. (Richard is actually from that ship.) Richard wants to die because his life has no purpose without Jacob. He can't kill himself, so wants Jack to kill him for him. Jack lights a fuse on the ship's dynamite stash for Richard, and then sits down to talk. Jack's betting that he's protected as well, that Jacob brought him here for a reason and that he won't blow up. I find myself begging begging begging that the dynamite goes off. I mean, that would be both unexpected and the Greatest Thing To Happen To Jack. Tragically, Jack was right. Of course he was. He and Richard ain't goin' nowhere.
At the end, they all head to the beach, and Sun reunites with Hurley and Jack. We see a periscope rising up from the ocean. There's a submarine. Piloted by Charles Widmore.