Taking place after Wicked as They Come, this original eBook features a mysterious lady and a reclusive mechanical genius who find love and danger in a traveling circus. 

An elusive woman arrives at Criminy’s doorstep with a steamer trunk, begging for a position in the caravan to perform her unique new act. She opens her trunk to reveal a menagerie of brilliantly colored butterflies. The woman, who calls herself Madam Morpho, is on the run from a dark past in London, where she was forced to leave her equipment behind and abscond with only her tiny performers. 

Playing a hunch, Criminy hires Madam Morpho on the spot. Taking her down to meet Mr. Murdoch, the reclusive talented engineer who keeps the carnival’s clockworks running, Criminy instructs them to work together to design and build a groundbreaking new circus for the butterflies. Amid the magical ambiance of the circus and the hint of danger from Madam Morpho’s pursuers, she and Mr. Murdoch soon find that their scientific collaboration has produced chemistry of a more romantic kind.

While I didn't necessarily enjoy this short trip into Sang as much as PECULIAR PETS there's no denying that the more I read of this world the more fascinated I am.  Imogen serves as a good counterpoint to Tish (from Book 1).  Whereas everything is so new to Tish (she's a "Stranger", someone who fell into Sang from another world) and she reacts with both wonder and fascination, Imogen has grown up in Sang.  She knows the dangers of the world, but makes a conscious decision to not let it run her life.

While Criminy (as well as others) make appearances throughout the story, this is very clearly about Imogen and Mr. Murdoch.  The two connect quickly, but the sexual tension is rather minimal.  Its not that its not there, but Imogen is a scientist; one who wasn't ever shown affection or love, who values people based on their actions.  Murdoch by comparison is reclusive, taciturn and hard to read at first. 

Despite Criminy's utmost confidence in Tish, and Murdoch's belief that all will be fine because of this, there's a palatable tension.  What is Imogen running from?  What is the real deal with her previous employer?  What is so special about the butterflies?  Many of these questions are answered, with an ending that suits each person well.

I wouldn't say its necessary to read the first book, not if you want a taste of the world and Dawson's writing before committing.  Some things are offhandedly referenced (like Casper, or Tish's abilities), but nothing much is said about what happened in that book.  This does make a good introduction to the world of Sang and Criminy's Clockwork Circus and an entertaining addition to the world at large for veteran readers.