Tony clearly had a joke ready in the wings for that by the way he smiled with dazzling depravity at Bruce, but Bruce managed to bait Tony with the trump card; talking about how brilliant he was. He slung an arm around Bruce's shoulders instead as he led them through the door, more torches lighting themselves as they approached down this new hallway, which looked far less moldy though not exactly well kept. "She's cute, right?" he beamed, the spark whizzing around them to map the hallway. "It started as a way to interpret the wards on the 'puffs dorms, but then I realized, if I just built her into the foundation, she could map the whole school. Wakes me up when someone breaks one of the wards in the middle of the night, but its pretty handy. I mean, she mostly keeps records, I still have to do the legwork, but it's a start." It was warmer here, too, Tony realized, after he had bundled up his blanket-cloak to drape over his neck like a scarf. Maybe it was the torches. But the limits of the sparks tether to the castle were tested as the hallway opened up into a cavern-- or, rather, a massive hole in the ground, artfully carpeted around the perimeter as though they wouldn't noticed the chunk of Earth roughly excavated down into a dripping, distant darkness. The spark immediately darted for it, only to wink out unceremoniously as it dipped past the lip. So much for Tony's brilliance.