Impostor

In the depths of space, a spaceship and its crew are fighting to survive. Because there is an impostor among them, they must remain watchful. If they are left alone with another person, especially if that other person is the impostor, they must be aware of vacant rooms and be prepared for an attack. The Impostor is hell-bent on murdering everyone and will go to any length, even destroying the ship, to achieve his goal. He is both astute and cunning. He can hide in dark corners and wait for his target, or he can leap from a ventilation shaft and attack from behind. It's impossible to find him among the crew members unless he makes a mistake. Would you do something like that, Impostor?