When a friend says “nothing’s wrong” and then slams the door, believe the door.

Words are the easiest part of a message to control, so they are the first part people use to cover something. The body gives it away: the door, the short answers, the sudden plan to leave. Taking the words at face value is often a choice you are making because the alternative means getting involved.

Go back later, when nobody is in the doorway, and say that something seemed off. Keep it to one offer rather than an interrogation. If they still say nothing is wrong, let them, and make sure they know where you are.