To avoid their race ending in ruins, teams go back to school and pick between a game of Pok-A-Tok or an ancient number puzzle. Finally, they must memorise the months of the complex Mayan calendar.

It's sink or swim in Mexico's coastal city of Campeche, where teams must eat edible insect cuisine, shoot down pinatas, and make rope out of henequen plants before a spiritual dip in a local sinkhole.