The Setting: Think about a month-long cruise to Hawaii, except it's not quite the paradise you once envisioned. Through a sinister lens, you're trapped on open water with upwards of a thousand strangers. So much could go wrong if the ship lost connection to dry land.
The Premise: There are plenty of ways to make a cruise ship horrific. What if the whole crew was secretly evil? What if there was a serial killer on board? What if a crazy sea monster tried to eat everyone? No one would be able to help. You'd be freaked out and you know it.