Archeologists make a bone-chilling discovery when they unearth 20 mutilated skeletons in Mexico; investigators use advanced forensic analysis to examine the bizarre burial and reveal an ancient case of Mayan mass murder.

When experts discover a 500-year-old grave, they find mysterious red skulls, pointing to a shocking mass sacrifice; experts use the latest technology and state-of-the-art forensics to investigate what happened at this horrific sight.