That fateful Halloween night, Sirius makes a mistake that sends him running to adopt his niece through blood magic. Little Hermione becomes his salvation and his reason for living. Follow their story through Hermione's years at Hogwarts and through the second blood war. Slow-burn Harmony. Completely AU.

A promise made before the fateful night changed the future of Harry Potter-Black. Now on his fourth year, he has to face the Triwizard Tournament, his failing friendships, and live up to his ancestors. All of this while dealing with an increasing attraction to a French flower.