Mark came home from school to find his 3-year old little brother Fred missing. He called his friends Abby and Carl to help him look. He told them his parents left a little while ago and his dad had just fixed the vent system in the attic. Upon entering the living room, Abby immediately noticed dirty footprints of a barefoot child. She pointed them out to Mark. He looked at them and suddenly heard a crash above him. Carl ran out of the room. Where is Fred and where is Carl going?