Lost

The survivors of Oceanic Flight 815 have immediate problems: injuries, supplies and a beach far from help. Lost quickly makes it clear that the island has questions of its own, while the people arriving on it have histories they may prefer not to discuss.

The ensemble gives the mystery its staying power. A person who seems dependable in one situation can become much harder to understand once another part of their life is revealed. The flashbacks are most effective when they change the meaning of behaviour already witnessed on the island.

There are stretches where the continuing questions are more persuasive than the pace of the answers. Enjoying the characters is essential; watching only to have every puzzle resolved turns a substantial strength of the show into waiting time.

Start with the pilot and let the situation develop. For another ensemble mystery with a strong speculative hook, Manifest is a related option, though Lost has the more distinctive setting and much greater range of character drama.