In its six seasons on ABC, the drama series "LOST" kept viewers on the edge of their seats with twists and turns, leaving many with unanswered questions and hopes for the answers to be revealed in the "LOST" series finale spoilers. However, just as the series provoked debate and theories as it aired, the "LOST" series finale did not deviate from that path.
Prior to the "LOST" series finale, viewers argued that the characters were not on a mysterious island, rather dead, having never survived the plane crash at all. Others felt the castaways had landed safely all along, with the island acting as the alternate universe. The sideways flashes in season six, showing each of the characters on both the island and in Los Angeles, California, only added fuel to the fire.
In spoilers for the "LOST" series finale, there was some closure as the sideways world was explained, however many unanswered questions remained. Finally the origins of the black smoke monster were revealed, with viewers learning that the monster was created after island protector Jacob was thrown into the powerful light by his twin brother, the Man in Black.
Havin taken the form of character John Locke, the smoke monster was stopped in his attempt to leave the island when Desmond uncovered the stone from the pool in the cavern. After Locke returns to his mortal self, Jack and Kate kill Locke.
Though Locke was out of the picture, the island's danger remained. Making the ultimate sacrifice, Jack pushes the stone back into place in the pool in the cavern. As he lays dying in the jungle, he sees many of his island mates finally leaving the mystical place for good via airplane.
Viewers also learned in "LOST" series finale spoilers that the sideways flashes during the final season showed each of the main characters in purgatory, negating a theory that the island was the purgatory, and was in fact real.
Now that Jack has died, he returns to the sideways reality. In the alternate universe, Jack is preparing for his father's funeral, but things do not go as expected.
Upon arriving at the church, Jack is greeted by not only his dead father, Christian, but each of the notable passengers from Oceanic 815 and the island. Initially confused, Jack soon learns that in purgatory time does not matter and while they are all now dead, the deaths occurred over a span of time after they left the island.
Just as they all met on the island, the "LOST" season finale spoilers reveal that all cast members enter the afterlife together as they were the most important individuals in each other's lives.