u/Capital_Factor_3588

a fic, where the order decides they will use sirius instead of having him sit at grimauld.

As the kids board the hogwarts express, sirius black stands atop of the train. he proclaims, that, now that voldemort is back things will change drasticaly. then he shoots the dark mark into the sky (taught to him by snape) and blows up an empty compartment before making an exit.

a good portion of the magical population witnessed the atack in person. it would boost dumbledores and harrys credibility like nothing else could