Well the episode starts like this''once upon a time there was an island where there was a strange woman and a ship around 24 BC lands by accident (see Black Rock,Desmonds boat,Oceanic 815,Aijira) where a pregnant woman gives the birth to 2 children (see Jacob and Man in black)and unfortunately she dies by Claudia the woman who was on the island already but we learn why these 2 people cannot heart each other and how The Orchid Station was built and the Wells also but we don't know who built the Statues,we don't know anything about Claudia or the real name of Man in black and the mysterious light the power of the island as the writers said but we have a sweet surprise where we have found a clue by the first season at the caves where Jack had found two dead bodies (see Claudia and Man in black)''.Many questions without answers but i hope the last episodes will reveal us more informations after all this is the reason that Lost became a great show.
Review of Across the Sea
