Jack is flailing around underwater. We can dimly hear Kate's voice screeching out for him. He makes his way to the surface. Hurley is already in the life raft, and Kate (holding Aaron), Sayid, Frank, and Sun are making their way to it. And then Frank finds Desmond floating face-down in the water. What do they call that position again? Frank flips Desmond onto his back and then he and Jack pull him to the raft. Sayid and Hurley pull Desmond's limp form into the raft, and then Jack climbs in and starts performing CPR. And just as you think you realize why we never saw Desmond in a flash-forward, a geyser of water erupts from his mouth and he starts coughing. And so they're all fine. Albeit trapped on a raft in the middle of the trackless ocean.
Flash-forward. Kate is asleep in her bed when she hears a creaking noise and wakes up. She turns on a lamp, and then her phone rings. There's just a clicking sound when she answers, and then a voice speaking some language she can't understand. And then she here's a louder creak coming from the hallway. Kate hangs up and runs to her armoire, where she fishes around and pulls out a gun. She makes her way to Aaron's room where she finds a blond woman leaning over his bed, holding his hand. Kate yells, "Don't you touch my son!" And then the woman turns around, and we see that it's Claire. Awkward. Kate's in shock. She starts to ask how Claire got there, but Claire interrupts her: "Don't bring him back, Kate. Don't you dare bring him back!" And then Kate wakes up for real. She runs to Aaron's room and finds him safely asleep in his bed. She kneels down beside the bed and takes his hand. Kate starts to cry, and then tells Aaron she's sorry. For what, she doesn't say.