Decisions

You decide to go on the sides. You don't want to touch the tracks and walk right next to the wall with your left arm brushing the wall. You walk for some time and feel an indent in the wall, then the indent turns to a hole approximately your height and width. You stand in front of the hole wondering whether or not you should enter. As you decide, a sound of metal screeching, or at least what sounds like metal screeching, echoes around you and in a scare you walk forwards into the hole.