This book is the follow-up to 'Touch of Evil' by the same authors and it continues the story of Kate Reilly, her werewolf boyfriend Tom and various other characters. The authors' take on the vampire/werewolf mythology is rather different than the norm with the Thrall being a hive mind with which Kate is linked following the events in the previous book.
'Touch of Madness' starts a month after the end of the previous book and Kate finds herself once again in the thick of a load of trouble. Some eggs have been stored and while Kate and the other Not Prey are in a meeting to discuss further studies the eggs escape. Kate and police detective Brooks do what they must to stop the infestation and find themselves being sued. At the same time Kate is approached by the vampires to find some other eggs that have been stolen, her relationship with Tom looks like it might have problems because he may be needed to sire more werewolves and Kate is sterile, plus her brother, who is in an almost-zombie state, is proving difficult to handle and may lose his place in the care facility; not to mention two evil and insane women are on the run and they both have it in for Kate.
There are several threads of plots all overlapping and that's what makes the book interesting. There are also several different 'baddies' who are after Kate or those whom she loves, as well as the confusion over good and bad with regard to the Thrall. Kate considers them evil parasites but she's beginning to discover this may not be entirely correct.
The relationship with Tom was well established in the first book and in this book it continues and deepens. Her relationships with other people, such as her brothers Joe and Bryan, come under more scrutiny and we see a lot of heartache amongst them. Kate does come across rather like an early Anita Blake, always in the thick of things, internally conflicted about her actions but brave and almost suicidal at the same time. Fortunately the people around her take care of her and seem amazingly supportive - most of the time.
I initially found this book rather difficult to get into, mainly because I hadn't read the previous book in the series. However after the first couple of chapters I found myself drawn into Kate's world and learning about the events that have made her the person she is. There was an awful lot of backstory from the first book and it was doled out in small portions and that meant I didn't always understand everything but I found the book very enjoyable nevertheless and the non-stop action made it an exciting read. The fact that it was written by two people was never apparent as the writing style felt congruent and smooth without the odd jarring notes that twin authorship can sometimes bring. In conclusion, this is an excellent book and very exciting but it is probably worth reading 'Touch of Evil' first so that there is less complicated plot to work out.