BEFORE THE CRASH:
- A spinal surgeon at the same hospital with his father, Christian, also a doctor
- Successfully operated on a woman, Sarah, whose broken back was supposedly irreparable
- Married Sarah, who later left him because he worked too much
- Reported his alcoholic father to the hospital board after a patient died under his knife
- Went to Australia to find his missing father only to discover he'd drank himself to death
BEFORE THE CRASH: He was a spinal surgeon, just like his father and is driven by his need to help others. He became the reluctant leader who solves disputes with reason but not afraid to use guns or torture if necessary.
OFF THE ISLAND: Rescued as part of the Oceanic 6 and began living with Kate and young Aaron. He eventually proposed to her, but things soon fell apart. Working with Ben, he then became obsessed with reuniting the Oceanic 6 to return to the island.
RETURN TO THE ISLAND: Aboard Ajira Airways Flight 316, a time flash sends him to the island in the '70s, where he becomes a member of Dharma as a workman.
Survived the detonation of Jughead and is back in the present-day time period on the island. Nominated as a candidate to take over Jacob's job as protector of the island.