Through My Veins (слэш)

"Potter," Slughorn shot out immediately, spittle flecking Harry's bare stomach. "He's back."
The serial killer who murdered Harry Potter's parents twenty one years ago has suddenly returned with a slew of new murders, and Auror Harry is put on the case, along with archivist for the Department of Mysteries, and new Auror consultant, Tom Riddle. As Harry's connection with Voldemort deepens, so does his friendship with the calm, ever polite Riddle. But soon Harry is caught so deep in Voldemort's conscious that he can't figure out where he begins, and the other man ends.
Or
A serial killer AU in which everyone still has magic and Harry has to fight to keep his sanity in the search for his parents killer, all while denying his attraction to the ever mysterious and handsome Tom Riddle.