The first cipher achieved everything the Zodiac Killer had wished for. He had fashioned using threats and newspaper rivalry maximum exposure for his handiwork, which was very quickly published by the Vallejo Times-Herald, San Francisco Examiner and San Francisco Chronicle. The failure of Zodiac to give us his name did not satiate the desire of some in the quest for the real identity of the killer, and was championed by Dr D.C.B. Marsh, president of the American Cryptogram Association, who on October 22nd 1969 in an article published by the San Francisco Examiner, stated "The killer wouldn't dare, as he claimed in letters to the newspapers, to reveal his name in a cipher to established cryptogram experts. "Zodiac" had not done this, Marsh suggested, because to tell the complete truth in relation to his name, in cipher code, would lead to his capture. I invite 'Zodiac' to send The American Cryptogram Association a cipher code-however complicated."
If we can provide a compelling reason to show that the near-Zodiac on the final line of the 340 cipher was actually intended to be deciphered to 'Zodiac', then we are left with the final two characters of the cipher to decode, thereby bridging the gap between cipher two and three.
Using the most powerful supercomputers in the world and the talent of some of the brightest minds in cryptography, the 340 cipher has failed to buckle. So, it's time to use the character of the Zodiac against himself, and his willingness to respond to the newspapers.
If the Zodiac Killer is responding to Dr D.C.B. Marsh, then he clearly isn't prepared to give us his name immediately in the November 8th 1969 '340 cipher', as the opening line in his April 20th 1970 communication would testify to. It would be over five months later that he stated "my name is". Therefore, the final two characters of the 340 cipher are the conclusion to an open-ended promise of something more to come, in similar fashion to "my name is." The Zodiac Killer certainly wasn't going to miss the opportunity to keep Dr D.C.B. Marsh and the public waiting just a little bit longer.
The final line or sequence of the 340 cipher probably read "The next cipher will reveal who the Zodiac is" or "I will soon reveal who the Zodiac is" - or something along these lines. This 'promise' can be seen in his opening gambit of the April 20th 1970 communication: "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you. My name is...."
The statement of "by the way have you cracked the last cipher I sent you" is superfluous, as he knows only too well the 340 cipher has not been cracked, yet, it also lacks his usual abrasive sarcasm. However, it is followed by "my name is", and therefore could be construed as the conclusion to his promise from the final line of his 340 cipher and to Dr D.C.B. Marsh, and the allegorical bridge between the two ciphers.
These six characters of the 340 cipher were effectively carried forward numerically and placed front and center of the '13 Symbol' cipher design. You will also notice that the two characters either side of three 8's (shown on the right), are both visible either side of the near-Zodiac on the 340 cipher. A total of eight characters and three circled 8's the common link or bridge between cipher two and three - in which the name of Zodiac played a pivotal part in the formation of the 'My Name is Cipher'. The story is now complete.
The Zodiac Killer stated on July 31st 1969 "I will not give you my name, but in this cipher is my identity." He promised in the 340 cipher, in a response to Dr D.C.B. Marsh, that he would soon reveal his name. Then, five and a half months later, on April 20th 1970 he stated "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you. My name is...."
Do ciphers two and three really contain a full and coherent message, not dissimilar to the 408 cipher solution, or had the Zodiac Killer taken Dr D.C.B. Marsh's advice "to send The American Cryptogram Association a cipher code - however complicated", and taken it a step too far?