I focused a whole lot on Jean in this one, to be honest. 
 I didn't think the big fellow had a romantic side, even though it was he drawn mostly to romance novels. 
 The book was fantastic, as usual, and Lynch threw in a few elements that I wouldn't have expected. He didn't do a poor job of it though, and rather then a random change in plot (glances at James Patterson's Maximum Ride books), he made it completely believable, though of course it wasn't so for our dear protagonists. 
 He mentions, even, in his Afterword that he didn't know much about nautical terms and practices. I didn't notice at all. In fact, I sat there reading and wondering how the heck he knew about all that. Turns out he didn't. Hmm. 
 "All hands to the starboard bow!" 
 As for Locke and Jean's development, they stayed the same as they were, but grew significantly at the same time. It's hard to explain, but Locke is still Locke and Jean is still Jean (besides the fact that they're also de Ferra, Kosta, Ravelle, Jerome...) in the ways that they are thieves. However, both of them learned a little bit about NOT being the Camorri Snivellus butt-trumpets that they had to be in the previous book (and I mean 'had to be' as in 'required to be'. Else they would have died. You have to give them that much.) 
 I also found it startlingly realistic of Locke's character not to even try to pretend to be a priest of Iono. Send them away with the blessing of the Crooked Warden, even if it means abandoning all hope of staying trustworthy. 
 All and all, I'm unable to wait for the third book. That's why I didn't. I looted the internet elsewhere to hunt out bits and pieces of the Republic of Thieves. ;) 
 "You're the Lamora boy, right?"