Excerpt from Turing's Delirium by Edmundo Paz Soldan, plus links to reviews, author biography & more

You turn on the computer and check your e-mail at both the public and the private address. You spit your gum out, put another piece in your mouth, and all of a sudden at your private address you find an e-mail consisting of a single line:

RZWIJWJWDTZWMFSIXFWJXYFNSJIBNYMGQTTI

You notice the sequence FWJ XYFNSJI. Frequency analysis won’t take more than a few minutes. Each letter has its own personality, and even though it seems to be out of place, it is betrayed, whispers, speaks, shouts, tells its story, misses its place on earth — paper. Who could have sent you this message? From where? You don’t recognize the address. That’s strange — only about ten people know your private e-mail. Someone has managed to get past the Black Chamber’s firewalls and is teasing your heart with a crude message.

All messages from within the Black Chamber come encrypted to your private address and your computer deciphers them automatically. Perhaps something in the program failed. You hit a couple of keys to try to decode the message. No luck. It isn’t encrypted using the Black Chamber’s software, which confirms your suspicions: the message was sent by someone unknown.

It is a taunt. For now, you had better do what you do best: frequency analysis. The j has to be a vowel: a? e? o? Common sense tells you it’s an e.

You soon know: it is a simple code ciphered by substitution, a variation that, according to Suetonius, was used by the emperor Julius Caesar. Each letter has been moved five spaces to the right, so that the j is really an e, the g is a b, and so on. XYFNSJI spells stained.

MURDERERYOURHANDSARESTAINEDWITHBLOOD

Who’s the murderer? You? Why are your hands stained?

Spanish edition copyright © 2003 by Edmundo Paz Soldán, English translation copyright © 2006 by Lisa Carter. Reprinted with permission by Houghton Mifflin Company.