"Nev ... I lived here for over two years," Hermione seethed. "I had to accompany Ron on his weekly inspections of the camp facilities. I know my way around the network of tunnels, and workhouses and torture suites better than most of the senior guards. I know all the blind spots, too, so I've got a better chance of sneaking around unnoticed than any of us. I'm the best option ... you have to see that."