There's some ammo and health in the crawl space, along with a hole that drops down to a room with two imps. Kill it, and then enter the small crawl space to the left. As you make your way down the ledge, watch for the imp that spawns below. The mechanism will carry the container-with you on it-back to slot three, from where you can jump onto the ledge on the side of the room. When the container is put down in front of you, jump onto the nearby cardboard box, press the number '3' again, and then quickly jump onto the storage container. Step up to the control panel in the center of the room and press the number '3' to call to you the storage container in slot three.