After four years, Remus had let curiosity get the better of him and he goes to find out the truth about Halloween 1981. Wherein Remus Lupin pays Sirius Black a visit in Azkaban to understand the Potter murders. "Sirius had murdered 15 people; punishment was necessary in such circumstances. And yet Remus couldn't help but feel compassion for Sirius." - when the seasons change on ao3