If you were onboard an airplane that crashed on a remote island inhabited by polar bears and a mysterious group of people called “The Others,” it’d probably be nice to have a doctor with you. Enter Dr. Jack Shepard (Matthew Fox), a survivor of the fateful Oceanic Airlines crash, and eventual leader of the crash survivors. At first, Shepard helps his fellow survivors on a physical level, helping to treat their wounds and other ailments. Later he helps them on a more supernatural level, ultimately engaging in a fight to the death with the “Smoke Monster,” the island’s evil spirit. And they say med school is hard.