Somewhere deep down in his gut, Tybalt recognised the ridiculousness of this situation. This sort of circumstance was one that he had long since outgrown, one that even the slight-figured youth beside him had well outgrown. Something that might have been nothing.
But acting like schoolboys was something Tyb couldn’t quite bring himself to forgo, and it was much too late to turn back the situation to pretending they were only guests who’d gotten lost on the stairwell. No, now they were rulebreakers out past curfew, and Mr. Holm was getting the real Hogwarts experience. (Tybalt had always thought, if not-quite-consciously - well, maybe it was only a gut feeling - that the castle took kindly to rule-breakers and mischief-makers, and had a delinquent personality of its very own.)
The castle could not save him from his own failures, of course, and his imitation of a portrait perhaps had been a stretch. He kept his ear as close to the tapestry as he dared, aware in the corner of his eye that at least Mr. Holm seemed to be suppressing amusement at the performance - as aware as he was of the footsteps, a muttered conversation outside. He was sure they were moving onwards now, sure that he could exhale now, and so, before he could help himself, Tybalt peeked outside, the tapestry rustling as he pushed out the edge of it.
Maybe they’d missed it... But. One of them had looked back. Had he imagined that?
All things considered, he might have, the exhilaration and adrenaline of the sheer possibility jumping the gun for him. Maybe the adventure had not been high-stakes enough for him yet. In any case... "Run!" Tybalt gave a yelp and launched into gleeful movement, barrelling Holm along in front of him with thudding footsteps into the dim windowless passageway. Up ahead, it wound left, leading them onwards and cutting through the castle until they tumbled out the other end into an entirely different deserted hallway, two floors above.