Earthling

Answer: There weren't any clues. It comes off as a total surprise during the reveal. But watching it for the second time, I did notice that she spoke very less compared to others and no one was suspecting her. Usually, that kind of character ends up being the bad guy.

Earthling

Answer: No. The devil is a deceiver and a trickster who can easily manipulate anyone so everybody in the elevator would not even think to suspect an old lady.

Answer: Yes, there are many clues actually. The old woman's reflection throughout the film always had black eyes. In one scene, they're backed against the wall, the elevator buttons look like devil horns on her head. When she goes to push the floor button, the color is red, rather than the green it is for others. The other two answers just don't pay attention.

Answer: Remember that Robbie wanted to become a doctor, and had he been able to achieve that dream he most likely would not have been drafted into the army as a combatant.

Answer: 1. Yes he'd be free once the war has ended or if he's injured and hospitalized. Also, the release form might have specified the duration of service. 2. Yes he would have, but he was already in prison before the war was imminent.

Earthling

Answer: No. He was murdered at age nine. The movie uses creative license to bring up the suspicion that he could have somehow survived to create a dramatic hope in the end. Moreover, the killer was very unstable and retracted his testimony more than once. There is no solid proof of the boy surviving the killings. The police even found partial evidence of Walter Collins at the burial site. See the Wikipedia article for more information.

Earthling