Teams attempt to descend face first down the side of a skyscraper. Later, they are required to retrieve a clue from a tank filled with sharks.

The fourth edition of the 45,000-mile race around the world concludes as the final three teams dash to the finish line in the western U.S., after stops in Australia and Hawaii. The pairs vying for the $1 million first-place prize: married gay partners Reichen and Chip; best friends David and Jeff; and engaged couple Kelly and Jon.