While I enjoyed this book at first, after reading Storm Front by Jim Butcher after it I did have a bit of a rethink. The story was good, hooking me in and wanting to know more and find about more but then I couldn't help notice the similarities between The Unicorn Crisis and Storm Front. In a way it could work to Rosenberg's advantage if a reader is looking for a series similar to the Dresden Files but at the same time having quite a few similar aspects doesn't make it original for me. While I like books inspired by others I still look for the author's own twist on it.
Both David Ash and Harry Dresden have a dodgy past where their supernatural actions could have got them arrested and killed. They both have a strong relationship with a cheeky otherwordly being: Llewellyn the elf for David and Bob the spirit in a skull. They both work closely with a female on their separate mysteries to solve. Sometimes you need to change things round a little bit to make it different but nevertheless I read the whole book, drawn in to this world of Summoners where all your famous myths and legends such as Oberon, Gods and Goddesses, unicorns are true and come from another world. Summoners have the power to bring these creatures to our world and send them straight back and that's where our mystery lies for David Ash. A unicorn has been brought into our world and it looks like the unknowing Summoner might simply be a pawn in something much bigger and dangerous, that has our magical MC facing the demons of his past. I can be a sucker for magic and crime going together so I wasn't disappointed.
I think the strongest aspect was the humour. Rosenberg gladly brought in the famous, mischievous Puck who was borderline psychotic but lived up to his cheeky reputation by creating more problems for Ash, at one point deciding to redecorate his entire house. A constant nuisance that brought some light comedy to contrast against the dangers in the plot.