Everyone Alive!AU
OC (Black Brother's little sister)
Grownup!AU

The Marauders but everyone is grown up and alive. Regulus had reconciled with Sirius.

OC Nova Walburga Black, younger sister of Regulus and Sirius who got left behind and presumed dead when word came out that the House of Black was finally empty.

Basically, they go to this bar and they see Nova performing there, singing