Sum up 'Lost' please?

DHARMA were scientists studying the unique properties of the island.

The Smoke Monster is Jacob's twin brother, both were born on the island. The protector of the island killed their birth mother Claudia and raised them. Jacob became the new protector and Fake Mom destroyed the other twin's chance to leave the island. Enraged the other twin killed her. Jacob threw his brother into the Source cave which the protector takes care of. It killed the body of Jacob's brother but because Fake Mom made it so they can't really hurt each other, his spirit and/or mind survived and became Smokey that can scan minds and take the form of dead people you knew to minipulate you, pledging to find a way to get Jacob dead and leave the island and probably kill everyone in the world because he hates all people.

Jacob brought people to the island as candidates to take over the protector job and kill his brother if possible. Desmond Hume who was physically responsible for the crash and threatened by the Man In Black, (the only name we got for Jacob's brother),saying he would kill Rose and Bernard two of Desmond's friends deactivated the Source which made Smokey (now in the form of deceased plane crash survivor John Locke) human and kill-able. He is killed by Kate Austen and the new protector from the plane, Jack Shepard, but MIB stabs Jack fatally.

Jack saves Desmond and puts the Source back in place after passing the protector role to Hurley from the plane He later dies as he sees a the plane from the second crash fly away with Kate, his now mentally damaged half-sister Claire because of MIB, (they didn't know about their relation until a few days before the final battle) and Sawyer, Miles, Richard and Frank the pilot. Sayid, Sun and Jin are killed in MIB's trap that Sawyer fell for.

Hurley hires Ben Linus as his No. 2 who was the leader of the Others, Jacob's original group and the villians of the first 3 seasons. Ben suffered much for the island all for Jacob supposedly, but Ben never got proof Jacob was real, except for the fact Richard Alpert didn't age (Jacob's advisor to the Others current leader, for around 125 years.) Minipulated by MIB as Locke, Ben killed Jacob. He was broken then, lost all of his fighting spirit so Hurley gave him a purpose.

In Season 6 we see a realm where they do not crash and things are different, not possible in the orginal time-line even if the plane never crashed. The writers only call it Flash-Sideways. We assume this is because they altered thirty years of histry at the end of Season 5. In the end we find out it's them as sprits after they all died *eventually* Jack's Dad said some died before Jack, some *long after* him. They did NOT die in the plane crash. All of the first 5 seasons and the island half of Season 6 was real. We do not see Claire or Desmond die because they out-live Jack having full lives but eventually dying like all people do. Those that could work through their issues they never got over in life, got to reunite to "move on" at a Church. Ben stays in the Sideways even after he's dead by the end because he stil has issues to work out with many people who do not know what the Sideways realm really is yet.

Like Jack and Juliet's son wasn't real. It was so Jack could get over his father issues by being a good father and tell himself (represented by David what he wanted to here from Christian) Christian did love Jack but was working so hard he didn't notice how isolated Jack was until it was too late. Juliet was the mother because she never got to meet her nephew, saw all the women and unborn babies die, and the hints she was pregnant when she died with James' child. She finally got to experience motherhood in the Sideways. It's also a nod to Juliet/Jack not working as a couple.

Aaron at the Chruch isn't real either since we know he lives until at least age 3 from Season 5. But for the group from the island to feel whole, and like Charlie knew Aaron, they made a newborn version to join them together.

Sun and Jin only got to be parents together when during the pregnancy on the island, Jin never got to meet the daughter he named so they made the illusion that Sun pregnant in the Sideways.

In the 12-minute DVD epilouge, caled "The New Man In Charge", set in 2010 it shows Ben and Hurley getting Walt out of the mental hospital and implyies he was always meant to be leader of the island after Hurley. It also hints that Walt can help his Dad not be a Whisperer forever and go to the Sideways realm. It answers pregancy problems, (which implies they were caused by the Incident, making Juliet responsible for why she first came to the island, and Sun could have stayed on the island after the Hatch created by the Incident was destroyed but their's no way Juliet could have known any of that). It also answers: Room 23, Dr. Chang using different names in the Station films, polar bear Orchid connection, food-drop and the Hurley Bird.