mrwaverly:
I like to think that in the interim between 'The Angels Take Manhattan' and 'The Snowmen', he was not actually retired, but sticking his nose into odd corners of London, righting wrongs that the police couldn't, perhaps even going as far as to seek the help of Jago and Litefoot [from the story 'The Talons Of Weng-Chiang, and several excellent audio adventures]. You just KNOW he couldn't just sit twiddling his thumbs...