[Hmm.] Bella considers. [You can see magic through the magic door just fine. I could leave a star by the exit in Alice's lair, the door to which is just around the corner from the door to your building, and you could hang around near the door but not go through it and inspect from there. Nothing much for spies to see, and I think we have to expect them to look or I doubt Libby would have been so willing to keep you unwishable. Would that do the trick, do you think?]