Their plane was torn apart and tossed
Onto this island. Now they're lost.
I have not seen all the episodes, but from what I've seen the explanation for "what is going on here?" is going to have to involve something supernatural or extraterrestial. Still, the show keeps my interest. What was a polar bear doing on a tropical island? Why can a crippled man walk now?
Maybe they were blown
Into the Twilight Zone.
Or maybe they're already dead, but don't know it. Like Bruce Willis in the "I see dead people!" movie.