In an exciting duel, the wild chase leads through all of London and Scotland Yard has to combine cleverly to find the criminal Mister X.
One player is Mister X, the other is the Scotland Yard detective. First, 25 board cards representing London are placed upright as a 5x5 grid between the two players. The Scotland Yard player only sees the backs and has to explore the city. Mister X sees the fronts and he is on one of the cards. Turn by turn, Scotland Yard reveals one of the fields, while Mister X may swap two (face-down) spaces with each turn. An exciting game of hide-and-seek begins!