"I can give you everyone currently in the library," William offered. "Spencer's with them, and I don't think anything will be able to get in unless something unexpected happens. Or unless the House-elves outside the doors remember how to Apparate." That wasn't something he wanted to dwell on right now, however. One thing at a time.
"Securing the Tower is going to be a nightmare," he told Pete honestly. "It's perforated with trapdoors and secret passages, top to bottom. I can start sealing them off, but it might be wiser to lead the children elsewhere." He cast a grim look in Pete's direction. "As you may have noticed, sweet teeth are not the creepiest thing going on around here at the moment."