The teams travel from their Pit Stop in Istanbul, Turkey to London, England, where they pay a visit to Abbey Road, made famous by The Beatles. Two teams explore flight options and successfully risk an earlier flight, while two others choose to play it safe with a flight that ends up coming in later. In England, the teams ride a ferris wheel called the London Eye and then participate in a Detour that requires them to make a classic choice --- Brains or Brawn. Uchenna and Joyce and Meredith and Gretchen both opt for Brawn, which requires them to stack boats, while the other two teams go for Brains and solve a series of clues leading them to the home of the legendary Sherlock Holmes. Seeing Meredith and Gretchen struggle, Uchenna attempts to help out before realizing that he's not allowed. Later, the teams do a Roadblock at the Millennium Dome in which they must drive a double-decker bus through a marked obstacle course. One team surges ahead, while a Yield puts the remaining three teams (thetvdb.com)