I'm a geek. When I was in college, I had a friend who was trying to put together a GURPS Illuminati campaign. I decided to go him one better and create one with multiple secret societies. Of course, it was a concept I'd stolen from the INWO card game. I'd read The Illuminatus! Trilogy by this point, after several years of only creating the impression that I'd done so by acting paranoid and muttering something in German every time the subject came up. (It really works!)
My college library wasn't big, but it did have a handful of books on secret societies and conspiracy theories, all of which I checked out. (The only one I can recall now is Akron Daraul's Secret Societies.) It was in those books that I first read about the Thuggee. I found them and their patron goddess, Kali, interesting enough that I decided to make them one of the five secret societies vying for world domination in my game. (Why 5? Because it's an important number for the Illuminati and because it was the number of survivors from the destruction of the Shao-Lin temple.)
I was particularly struck with some of the descriptions of thugs which emphasized not their bloodthirstiness but their upstanding social and moral character. One European had stated something along the lines that when they found out some Indian acquaintance was a thug, they were surprised, but still felt that person trustworthy in every regard except their Thuggee activities. It also appeared that the thugs ascribed their defeat to having forsaken some the rules that Kali had laid down for them. Curiously moral, these evil cultists, not at all like the picture I got from Indiana Jones or Gunga Din. I was struck by the idea of men involved in a cult doing things beyond the pale, who could turn around and pass not just as ordinary, but as the most upstanding men in their society. This sounded like a real secret society, and one who everyone seemed pretty clear had been wiped out, which in paranoid Illuminati-style terms was just an indication of how brilliant a secret society they were.
Even though the campaign never took place (nor my friend's), I remained fascinated with Thuggee. There wasn't much information to be found beyond what I'd read in those few books, except for a couple of novels that were hard to find. (In that pre-Amazon age.) I did read up more on Kali, who I found a fascinating and strangely moving spiritual symbol.
Occassionally, I'd do an internet search under thuggee or Kali. One day, it turned up a journal article by an academic named Parama Roy: "Discovering India, Imagining Thuggee" The paper looked at a lot of the existing documentation on Thuggee and came to what was for me a startling conclusion: the whole thing was to a certain degree a British invention, driven by Western notions of an exotic East, misconceptions, misunderstandings, a need to assert imperial authority, etc.
Instead of de-romanticizing Thuggee for me, it actually deepened my fascination. Suddenly, Thuggee wasn't just a cult but had the potential for being something of a mirror, a reflection of the colonizers' darkest notions of violence and power. This threw certain curious mirrorings into question for me. The strangles had all been hung, taking some interest in making sure good knots were used. Sleeman, the big anti-Thug crusader, had seemed like something of a thug himself, a morally upstanding man who had used deception and violence for his own ends. And, of course, Kali had started out with not one but two thugs. (Adam and Steve?) Thuggee had taken an unexpected turn; it had gone postmodern.
I wouldn't call them an obsession, but since then, there never too far out of mind. Sometimes they seem to crop up in unexpected place. I've thought of assembling a list of all the secret Thuggee movies. There's the Believer, with Ryan Gosling as an orthodox Jew who's also a neo-Nazi; that mirroring of victim/killer and meditation on holy violence definitely pegs it in this category. At the top, of course, would be Bill Paxton's Frailty, which is the probably the greatest Thuggee movie ever made. (No, seriously, does it make sense any other way?)
Oh, the book, that's right. I just finished this book, and I was going to say a few things about it. I don't know if this is the best book about Thuggee, but it's certainly the one I've enjoyed most so far. The author decides to go to India to investigate both the history of the thugs and modern day criminality. He doesn't find what he's looking for, but what he does is pretty interesting. This is really a book to read twice (this is my second time), the first to get frustrated at what the author doesn't find, the second to relax and enjoy the trip and the author's observations.