Explains in simple terms how to encode and decode messages in various ciphers, describes coding machines, and gives formulas for invisible ink.

Four women who worked as codebreakers at Bletchley Park have taken up civilian lives. Susan has collated data about a series of murders. She tries to convince the police she knows where another body is, but they are unable to locate it and dismiss her. She turns to her three friends and they work out where the next victim will be taken, find the body, and then decide they are the only ones who can track down the killer

Explains and illustrates twenty-nine codes which can be used to send secret messages or as brainteasers

Text and illustrations introduce various codes and ciphers and give examples of their use throughout history

A British spy trawler is accidentally sunk off the coast of a Warsaw pact county. On board the ship is a hi-tech encryption device called ATAC, which the British use to send launch instructions to their Polaris fleet. 007 James Bond's investigations leads to Greece where he meets Melina Havelock. She is out for revenge for the murder of her parents at the hands of the "Contact." James also meets Aristotle Kristatos and Milos Colombo. Evidence suggests...