牛津大学校徽

　　Arriving in London at the end of the 19th Century, the Doctor and Leela make friends with a police pathologist, Professor Litefoot, and learn that hairs taken from the clothing of a dead body found floating in the Thames seem to have originated from a very large rat. 　　The Doctor's investigations take him first to the sewers, where there are indeed giant rats on the loose, and th... (展开全部)