"I can't say how much we'll have, after tonight. ... It has to be something - secure, at least. It embodies protection." He'd never heard of anyone using anything but something happy, and hadn't imagined that a boy who had grown up with literally every advantage might come up empty on that particular point. it made him wonder - but that wasn't for tonight, either. Spells were meant to be tweaked and finessed, and there was nothing wrong with experimenting, so long as one was prepared to endure the consequences. Let him try. "You might think of something comfortable, if that comes more easily to mind."