(Sorry, this time I don't have a picture of the book, though the owner is the same relative who lent me the books The Undercover Economist and Mokshagundam Visvesvaraya.)
And with this, I have read all of Simon Singh's books. Yay! (I think.)
I really enjoyed this book as much as his other two books. The passages talking about the cracking of the Enigma encryption system were like déjà vu after reading The Code Book. I also enjoyed reading about all of the tension and drama surrounding the various developments and failures leading up to the proof of Fermat's last theorem (though there seem to have been an awful lot of people who took their own lives in the process, unfortunately). It reminds me very much of Big Bang, as the material is presented in a very accessible format, and the focus is more on the developments and characters involved (as the end result is already known from the start).
I would recommend this to anyone even remotely interested in math, history, and puzzles. For readers in the US, however, note that while the UK edition is called Fermat's Last Theorem, the US edition is called Fermat's Enigma.