Holmes looks helpless. "I understand, but I don't have the manpower to watch everyone in town," he scribbles hastily, frowning. "And if what you suspect is true, quis custodiet ipsos custodes? All I can do, I have done. I will amend my instructions to include anyone who seems to be acting in an unfamiliar fashion." He looks from Severus to Dumbledore. "Any other suggestions you have would be welcome."