They got back. I never thought it would happen so quickly. The episode was amazing from start to finish with all the right elements of intensity, drama, mystery and balls-to-the-walls mythology. Where to begin? Tonight we had: a new dharma hatch off the island; the reunion on board the plane; the disappearance Aaron (Kate's line to Jack was historic); the odes to past characters (Marshal, Charlie); the allusion to the pilot episode; Desmond telling it like it is in typical amazing Desmond fashion; Locke's tragic suicide note; the revelation that Locke killed himself... and, oh yeah, they returned to the fraking Island.
The last 10 minutes could have been an episode all by itself but no, the writers gave us so much more. Everything from the exchange at the pendulum to Jack taking his leap of faith, this was vintage LOST. I fear that Penny is dead. I wonder what happened to Aaron. I am suspicious as to Ben's full role behind puppeteering Sayid, Hurley and Sun's decisions to board the plane. Why did Hurley have the guitar? Why was Sayid with an Air Marshal? Lapidus was the pilot! We're not going to Guam, are we?
Ms. Hawking told Desmond that the Island isn't finished with him yet and he said that he was finished with the Island. Ben told Jack that he was sidetracked and Kate told Jack that she'd go back so long as he never asked about Aaron again. So much was said but perhaps Jack said it best in season 3 when he said we have to go back.