The Amazing Race Preview for "This is the Most Stupid Day Ever"

The remaining teams keep racing in China. 

Teams must travel to Jade Drago Mountain River where they will saddle up a yak and lead it across the river for a photo with a tourist in order to receive the next clue.

After losing all sense of direction en route to the airport and their passport twice, a Racer's frustration threatens to get the best of their team, on THE AMAZING RACE, Sunday, March 13 (8:00-9:00 PM, ET/PT) on the CBS Television Network.

Amazing Race 18: Unfinished Business Debuts Tonight

Teams from past seasons return tonight for the 18th installment of The Amazing Race.

This show tests the teams smarts, brawn and ability to get along and is captured in stunning video that will be broadcast for the first time in HD.

This time the show enlists losers from season's past for a second chance at the show's $1 million prize money.

Many fan favorites are back including "cowboys" Jet and Cord McCoy (season 16), sisters LaKisha and Jennifer Hoffman (season 14), Gary Ervin and his daughter Mallory, Miss Kentucky and Miss America runner-up (season 17); erstwhile NFL cheerleaders Jaime Edmondson and Cara Rosenthal (season 14); "goth couple" Kent Kaliber and Vyxsin Fiala (season 12); Margie Adams and her son Luke, who is hearing impaired; and Harlem Globetrotters Nate "Big Easy" Lofton and Herb "Flight Time" Lang (season 12).

The race will last several weeks and take the teams once again around the world.