The Lost 21

Sirius refused to stay and serve another twelve years in Azkaban. Upon breaking out, he sought the one wizard that could clear his name, Albus Dumbledore. After convincing the older wizard of his innocence, Sirius is sent on the biggest mission of his life. Why is he dressed like Mrs. Figg and why does Dumbledore keep bringing over cats? Companion fic to Time Traveling Marauder.