Sirius had been leaning just outside the main door to the castle, having a much-needed cigarette when he'd started chatting to Dora over the network. It had been weird talking to the older version, and the sudden appearance of his little cousin as he knew her had been something of a pleasant relief in the middle of all the insanity. The thing with him and Regulus had put him on edge, hence the sudden smoking relapse, and a large part of him had been considering just backing away and hiding out with James until this was all over. But he couldn't very well leave Dora waiting, could he?
After finishing off the cigarette, which he guessed counted as 100 counts, he headed off into the castle. Thankfully, older Dora had told him her room number, so that gave him a place to start - the younger version of his cousin probably wouldn't have gone too far.
So Sirius began to search, peering into rooms and cupboards and behind suits of armour and around corners. This would be a lot easier if he had portraits to ask...
Finally, however, he came to a likely looking room, full of furniture and apparently uninhabited. A bit suspicious then, that the door the had been left ajar. Sirius sloped into the room, ducking his head to avoid banging it, nearly stumbling on an overturned chair. He bit back a crooked grin, stopping and ducking to pick it up, subtly giving the room a sweeping look. One of the cabinets had a door cracked, and a scent somewhere, hidden under dust and the slight smell of smoke on his clothes, made Padfoot shift somewhere in the back of his thoughts.
Sirius straightened up, giving a pantomime stretch and a yawn. "Well," he announced to the room in general. "I don't think Dora's anywhere. Maybe a dragon ate her." He wandered over to the sofa, settling down and bouncing experimentally. "Maybe I should just take a little rest here instead..."