Regulus was right -- neater solutions would have to wait until later. Most of the ghosts weren't enemies, but there were living, breathing, wand-wielding Death Eaters trailing in the door.
"Expelliarmus!" Sirius shouted, aiming at the one in front, but he wasn't counting on the magic he had available here. Over the last month, he had grown used to putting every ounce of force he could muster into each spell he cast, and now his simple Disarming spell not only disarmed the cloaked man, but sent him crashing backward. His wand flew at Sirius like an arrow, and with a yelp, Sirius jumped out of the way, letting the missile sail pass him. It clattered against the floor nearly to the far wall.