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.

Tom Riddle has a natural affinity towards passive legilimency. He grows up completely convinced everyone around him can also read minds, but they are too stupid to utilize the skill properly. Being surrounded by idiots is hard.