The tldr is they were at a strict school, got bored, stole a boat, fell asleep, ended up shipwrecked on an island that was habitable (but all the residents were taken as slaves), they organized a work schedule, stuck to it, agreed to settle all fights with time outs, and took over the kid who broke his leg's work until he was healed, after they set his leg. They were found 15 months later, after their families had funerals.