Maureen Johnson is awesome and I really enjoyed the first and second books in the Shades of London series — though I do admit to being a little frustrated with Rory in the second book (The Madness Underneath.) TW particularly enjoyed Johnson’s descriptions of rain in London – spot on.
I just downloaded the free prequel, The Boy in the Smoke and I’m looking forward to reading the other two books in the series. UPDATED 10/28: I read The Boy in the Smoke prequel. It was excellent!