According to several Maya calendars, time will end on December 27, 2012. A man discovers that if he performs human sacrifices at ancient Maya sites in Mexico's Yucatan Peninsula, the location of a valuable key to extend time beyond that date will be revealed. He must consummate the first offering under the full moon on a Mayan equinox. Russell Palmer, a Los Angeles professor of Central American civilizations, learns of the first sacrifice and rushes to Cancun to prevent future murders. Frustrated by dubious police officers and haunted by an unfortunate incident in his past, Russell must convince the wary authorities that he has well-founded intentions as the frantic search to prevent more sacrifices and to find the Maya key leads Russell and the police deep into the tropical jungles.