Jack, Kate and Hurley make it back to the island. But Ben, Sun, Sayid and a plane full of other people are unaccounted for. Jack's happy to be back on the island as he makes an impressive dive off a cliff and wades around in a lagoon. How Hurley and Kate were made to come back isn't yet explained. Also not explained is how the Dharma Initiative built The Lamppost or how they knew about the island in the first place to build The Lamppost to find it.
This was an okay episode. Why is Jack's hair so bad? Where did Jack's grandfather pop up from? Why is Kate coming? Where is Aaron? Why was Ben all bloody? Are Desmond, Penny and little Charlie okay? Where is Ji Yeon? Who is with Sayid? What is Hurley doing there, since he obviously doesn't trust Jack? Where did the Ajira Airways plane end up? Why is nobody on Ajira Airways at all freaked out about having five of the Oceanic 6 onboard? How did they get to the island if the plane didn't crash? Why is Jin driving a Dharma van?
"Why do you think you were never rescued?"
"The other people on this plane, what's going to happen to them?"