The rating might have been higher if it were not for the narration.   The narrator had an old fashioned plummy English accent which made Kel come across as a middle aged stodgy Englishman, like the father from Mary Poppins (I know, very specific but trust me).  Kel sounded like he was Lila's father not a potential love interest.  And keeping with the musical theme, Delilah was Eliza Doolittle of My Fair Lady.  
Again so hard to imagine any romance between them 
And without the burgeoning romance the story was slow.  Lots of time spent on interesting characters who don't make it to the end of the novel.   So by the end all you have is a mutual understanding between Kel and Lila and hints of adventure but no more or less than where they started.   
I had to listen at a faster rate and it still dragged.  

I like the author's writing and I'm not looking for a fast burn spicy romance after reading the Many Lives of Addie LaRue.   

I am holding out that the rest of the trilogy holds out better on paper.   There is enough potential in what's left at the end of this novel for some promising developments.