Theo, the patron saint of patience, did what Draco couldn't: explain something for the thousandth time. "Harry, I've told you. I had time to make two of them, and that was pushing it. They'll work in that room, because it's relatively contained, with only one window and two means of ingress or egress. The Chamber, at least according to the blueprints, is much bigger. It has a skylight, and a massively high roof, as well as at least six doors. All of that matters because the gas will get dispersed and the more space there is, the farther it has to go and the thicker it has to be in order to be effective." Theo paused, taking a deep breath before going on. "Plus, if we hope to get Hermione's magic back, we need to know where it's kept, how it's kept, and we have to give them a chance to curse one of us." Draco nodded, not taking his eyes off the building across the street. He supposed it was a good thing that he couldn't see Weasley, but it made him uneasy all the same.