Death Eater Takes a Holiday

Albus spells a few Order members back to their seventh year age, and sends them to spend time at Hogwarts for a holiday. The Headmaster’s intent is for them to learn that Harry is indeed mature for his age, so that he will be accepted as a full member. What will happen when Severus returns from his time as a teen, to find he has spent the better part of the week entwined with a certain Gryffindor? And, how do their lives change afterwards?