1981. Voldemort and Dumbledore are trapped in a magical bubble, but the war rages on, even as the factions they built start to quarrel and splinter. The Aurors have Unforgivables at their disposal; the Death Eaters are killing their own; the Order's morals are starting to slip.
Severus Snape, you have plot awaiting, a willing Death Eater patron, and a Lily eager for you to be around.
Senior Death Eaters, the young'uns are running wild without your stern supervision. Lestrange Snr especially (not) wanted by his sons, and Cygnus Black or Rosier Snr have a Druella already in play.
Arthur and Molly Weasley, the Prewetts are trying their best to protect you from the rage of Bellatrix. Maybe you'd like a say for yourselves?
Edgar Bones, you're "missing", presumed on serious Order business, and your Auror sister is pretty frantic.
Fenrir Greyback, while Voldie's no longer holding your leash, just how much mayhem could you be causing for wizarding Britain?
Head Auror Patil, your troops are in need of leadership. Barty Crouch Snr, your whole department needs a firm hand. And the bloody Minister keeps sticking her nose in.