At heart, this is a steampunk vampire novel, with undertones of romance. As steampunk, I thought it worked well, racing along at an entertaining pace and providing genuine character development. The vampire element, too, has progressed nicely, in particular with the characterisation of Prince Cesare, and those he has gathered around him. An intelligent vampire is always far more menacing than an animal, and Cesare's growing ability to think outside the box provides some clever plot twists. It is this element more than any other which serves to raise the series above the standard blood-sucking fare. This time around I found Adele more convincing as an action heroine, and the Greyfriar more credible because of his exposed weaknesses, and the occasional poor strategic decision. The one element that wobbled was the romantic angle. Yes, I could buy into Adele and the Greyfriar being attracted, and the bonds forged by their adventures growing steadily stronger, but that's about as far as it went. Unless I missed it, this relationship is never actually consummated, which given the desperate times they face, seemed unnatural and sometimes juvenile. These are adults, with adult needs and drives, yet they moon over each other like love-struck teens, seemingly unable to work up the courage to be grown up. Had this element been properly clarified in terms of whether a human vampire relationship was even possible, it would have further ratcheted up the tensions among Adele's allies, one of whom remains murderously opposed to her indulging in any kind of alliance or relationship with a vampire.

As with the first book in this series, The Rift Walker contains lots of enticing action, and some great moments, especially those featuring the supporting characters. Senator Clark, such a fabulous cartoon of the ugly American abroad, continues to rampage across the page like the proverbial bull in a china shop. Whereas, the vampire war chief Flay displays all the guile that Clark lacks, and because of this becomes a credible wild card for the future. The Rift Walker is very much a middle book, but the authors continue to write with flashes of style and panache which make this work a fun read.