Pretending to be Harry Potter (and Other Heartwarming Activities)

Harry Potter decides to give Tom Riddle a second chance at King's Cross Station by deciding to pass into the afterlife. A soul for a soul; the Horcrux that had been bonded to his scar is allowed to return in his place. Tom Riddle wakes up in a clearing in the Forbidden Forest—in Harry Potter's body. A lot of further shocking revelations occur after that.