Second in Archer's steampunk-romance series, "Glass and Steele", featuring a magical watchmaker and a gentleman with a clockwork heart. In this one our primaries investigate the disappearance of a magical mapmaker, while also looking for the master watchmaker who installed Glass's heart. I found it okay but leisurely-paced and overlong -- but I listened to it on audiobook, which I stink at, so that probably affected my enjoyment.