When a turn of the century prison reformatory is slated for demolition, a grisly discovery is made.  Hidden deep underground beneath the west cell block is a sub-basement structure that has not been entered in 100 years.  Inside are the skeletal remains of several brutally slain children.  As a CSI team arrives at the prison, an even more disturbing discovery is made that will eventually unveil a legion of seven demons and their even more chilling origins: each demon is responsible for one of the seven deadly sins.