I love the Modesty Blaise series of books, but this book is not one of my favorites. In fact, my feelings about "The Impossible Virgin" are mainly colored by my opinion that this book (the fifth in the series) marks the beginning of the decline of the series.
In many ways "The Impossible Virgin" is a typical Modesty Blaise story. There is a bad guy (Brunel) and he has some nasty henchmen (Adrian Chance and Jacko Muktar). Modesty has a run-in with the henchmen in Africa and defeats them. Later, Modesty and Willie Garvin (Modesty's loyal side-kick) outwit the bad guys once again, this time in London.
But then the plot thickens, and Modesty finds herself captured, taken back to Africa and subjected to brainwashing. I can't tell more without spoiling the ending for those who haven't read the book. It's very exciting and the plot includes many unexpected twists, more than average for a Modesty story.
The positive aspects that I love about the Modesty Blaise books are all present. The interesting relationship between Modesty and Willie, the intelligent and humorous tone and the deadly seriousness when it comes down to the life-and-death combat encounters. The bad guys are really nasty, the story is quite inventive and the descriptions of the locations sound authentic (although dated). The fighting scenes are unusual and memorable, especially an encounter near the end of the book where firearms are not viable and quarterstaffs are used against 10 attackers with machetes.
My biggest problem with "The Impossible Virgin" is that several of the plot elements are simply too unrealistic. Unfortunately, I can't go into detail without getting this review labeled as a spoiler. I also had minor problems with Willie's behavior vis-à-vis a certain young lady with emotional problems, Dr. Giles Pennyfeather (a major character) being so silly and the ending of the book being so sugar-sweet.
Despite my reservations, and the fact that this book is now 35 years old, I recommend it highly. It's still much better than most modern action thrillers.
Rennie Petersen