LOADING - PLEASE WAIT
Sign in now for full access to HISTORY content.
Sorry, we are not able to validate your channel subscription. Please contact your television provider.
Sorry, Adobe Flash encountered
an error during authentication.
Please reset your Adobe Flash license files and try again.
Sorry, you cannot sign in using your browser’s Incognito/Private mode.
The hunt uncovers a mysterious new cipher related to the Zodiac Killer, while the team's supercomputer uncovers a strange lunar pattern linking the killings. A taunting riddle by the killer may lead to a body. A second prime suspect emerges.
To view this page, you need to have Flash Player 11 or later installed.
Click here to install the latest Flash Player.