Part of the intercepted message includes the following cipher text:

The cryptanalyst begins by lining the assumed text beneath the cipher and looking for links that violate what is known about the Enigma.

Lining up the assumed text with the beginning of the cipher results in several incorrect links. The first is the H in Markworth which ciphers to an H. Since the Enigma cannot encipher a letter to itself, this is not a valid comparison.

In this example, the cryptanalyst finds only one possible position for the alignment without a letter encrypting to itself.

The next step in developing a menu to set up the Bombe is to diagram the links. The diagram shows the relationship of letters and their position in the message to other letters. In our example the letter A appears five times, twice in the cipher text and three times in the assumed text. It no longer matters to the cryptanalyst if a letter is cipher or assumed. This is