The Summer of 1943

It was the summer after his fifth year. Tom Marvolo Riddle had gone to Little Hangleton to find answers on his family heritage and was met with much disappointment. After making his first Horcrux and murdering his paternal side of the family and framing Morfin Gaunt, he had passed out in the middle of an abandoned field after getting as far away as he could to not be implicated at the scene of the crime. He wakes up in a room in the Leaky Cauldron to the mysterious boy who had appeared out of nowhere part way through the school year on Halloween, starting a series of unforgettable events.

Basically Draco and Tom spend a whirlwind summer together as roommates.