Meljean Brook's Iron Seas series is one of my favorite. She does steampunk and romance very well. I thoroughly enjoy a;; the main novels and the novellas just enhance the world she's already created. 
 Here there be Monsters tells the story of Ivy and Mad Machen (also seen in Heart of Steel. Yasmeen also makes a few appearances throughout the story. Ivy in desparation to escape London goes to Mad Machen offering herself in his bed in order to secure passage aboard his ship. Things take a twist when she second guesses her offer and ends up leaving in the middle of the night. Machen, for his part, was attracted to Ivy from the start. So when she leaves, he looks for her. For two years he searches for the "redhead who cheated him". He finally finds her and when he does he wants to make sure she doesn't leave again. 
 This is the perfect story to start out the series if you haven't yet. Meljean Brook does a wonderful job of introducing the alternate world and packing a full story into a little space. Very satisfying, I'm happy it was finally released as a stand-alone.