Order of the Phoenix era. No Voldemort. No Death Eaters. Grindelwald never fell — and now he's turned his eye toward the boy who's supposed to stop him. With Voldemort erased from this timeline, it is Gellert Grindelwald — older, patient, and far from finished — who has set his sights on Harry Potter, convinced the boy is the key to unraveling Dumbledore's resistance once and for all. As the wizarding world scrambles to catch up to a threat it thought belonged to the past, Dumbledore is forced to call in help from unlikely corners. That help comes in the form of Tom Riddle and Y/N, both entering their final year at Hogwarts, both trusted by Dumbledore in ways few students ever are. What no one at Grimmauld Place knows is that the two of them aren't just allies pulled into the same summer operation — they're in a relationship they've kept carefully hidden for over a year. When Dumbledore brings them both into the Order's inner circle, Harry, Ron, and Hermione are immediately suspicious. Two Slytherins, trusted with information the trio themselves are barred from? It doesn't sit right — and it isn't meant to. Tom is unreadable at the best of times, and Y/N's calm, aloof exterior gives nothing away, secret relationship included. As Grindelwald's plans close in and old loyalties are tested, Harry, Ron, and Hermione will have to decide whether the two Slytherins working alongside Dumbledore are hiding something dangerous — or just protecting something they aren't ready to explain.