Complex sentence: Jack drags himself back into the tomb and confronts the now-immortal Sloane and detonates a belt of explosives, killing himself but trapping Sloane in the tomb forever.
Split into simpler sentences: Jack drags himself back into the tomb and confronts the now immortal Sloane. He reveals a bomb that he strapped to himself and detonates it, killing himself, but trapping Sloane in the tomb forever.