Wendy Spinale gives us a dark, somewhat steampunk version of "Peter Pan" in this novel, with Hook being a young German officer who is seeking Gwen Darling -- who may be the only person immune to the so-called Horologia virus (interesting that the virus is named "time-teller" ... ). All of the adults, many of the boys ... and all of the girls except three that we can see in the tale have already died from the disease.
The book shows a post-apocalyptic London, with Lost Boys living in the tunnels of the former Underground and scavenging in order to survive. Hook's crocodiles are pets he keeps in the sewer ... and we see a couple of pretty bad scenes with them.
I could see the romance element(s) coming for miles, but everything is "clean" in terms of that angle -- despite the high level of violence in the book. It puzzles me a great deal that so-called "young adult" books are expected to never show teens experiencing more than the desire to kiss and yet they can deal with horrors all around them just fine.
Anyway, it was a quick, entertaining read. Parents considering this book for their kids may wish to read it first and be prepared to have discussions about death and disease.