Unknowns, Part the Second

A sequel to Unknowns. AU. The Dark Lord is dead, but life still has challenges to present. How will Harry Potter and Catherine Black grow in a world without war? How will Sirius Black adapt to peacetime after going to the brink of hell? The relics try to cling to the past while the world barrels toward the future. HP/OC, SB/OC, JP/LE, NL/HG, DM/AG, M for lemons to come