"He tried wandering in without permission. Once." The Doctor smirked, then shrugged, his expression bland. "It's more that he's always there, and surface thoughts... are hard to hide. He's fuming over the fact I'm here, and I'm willing to let him die if I feel it neccessary. He probably is aware I'm looking for him, if not particularly diligently, and that I'm entertaining the idea of killing him if he tries to come near Jack at the moment."