This is the first of the prequel series to the author's Mortal Instruments which I haven't read but the time in which this was set appealed as did the snippets I'd read while browsing at work. It was an enjoyable read. I like the world building she's done with Shadowhunters etc and I'm curious about Will's past. The clockwork creatures have potential too. 
 I'm going to have to read the next one in the series when it's released just to see what happens next with these characters.