Michael Dawson was a former construction worker and one of the middle section survivors of Oceanic Flight 815. Before the crash, Michael lost custody of his son Walt to his girlfriend Susan Lloyd and never got to know him. He had no access to his child until many years later when Susan died and he was awarded custody. After the crash, Michael had issues connecting with Walt, but the two eventually bonded during their time on the Island. He was in charge of the construction of the raft and attempted to leave the Island with Walt, Jin, and Sawyer to find rescue. However, while at sea they were attacked by the Others, Walt was kidnapped and the raft was destroyed. They washed up on shore, discovered the tail-section survivors of the plane, and headed back to camp. After communicating with Walt on the Swan station computer, Michael ventured a rescue alone, but was captured himself. When he returned, he shot Ana Lucia and Libby in order to release Benjamin Linus from captivity, and caused the capture of Jack, Sawyer and Kate, meeting his end of the deal he had made with the Others in return for Walt.
After leaving the Island on a motor boat with Walt, Michael returned to Manhattan, but racked with guilt, he became estranged from Walt and turned suicidal. In order to redeem himself he went undercover for Ben as a saboteur on the freighter Kahana, posing as a deckhand named Kevin Johnson. He was aboard the freighter when the C-4 bomb was found, and he froze its battery with liquid nitrogen to delay its detonation long enough for the Oceanic Six to escape, but the bomb eventually exploded, destroying the freighter and killing him.
Because of his actions, Michael did not “move on” and his spirit remained on the Island. Michael would use Hurley’s ability to see the deceased to try and aid his friends, and could be heard among the whispers.