choose to double the total value of any one question by pressing a gold "Doubler" disk while the balls are falling. The maximum possible amount that a team can bank in this round is £37,500 in the first three series; this was later increased to £45,000 for the fourth series. The values on the board range from £1 to £2,500, and are arranged as follows: Round 2 At the start of the second round, the contestants are separated from each other for the remainder of the game. One enters an isolation chamber behind The Wall, while the other remains onstage. Two green balls are played simultaneously, dropped from zones chosen by the onstage player. Three multiple-choice questions are then played, each with three answer choices. The onstage player is shown only the answers to each question and must decide which zone to use, based on how confident he/she is that the isolated player can answer correctly. The question and answers are then presented to the isolated player; after he/she responds, the ball is dropped from the chosen zone. A correct answer turns the ball green and adds the value of the slot it lands into the team bank, while a miss turns the ball red and deducts the value. The isolated player is not told which of his/her answers are correct or given any information on the team bank. The onstage player is offered an opportunity to "Double Up" on the second question and "Triple Up" on the third; these options allow him/her to play two or three balls from the selected drop zone instead of one, respectively. After the third question, if the banked total is at least £3 (as the least that could be lost from two red balls is £2), two red balls are dropped simultaneously from the same zones that were chosen for the initial two green balls. The maximum possible amount that a team can bank in this round is £199,998. In the first three series, two initial green balls were played from different zones chosen by the onstage player, and a team could bank up to £199,998. Beginning with the fourth series, seven initial green balls are played in a "SuperDrop," one from every zone, and a team could bank up to £474,998. The values on the board range from £1 to £25,000, and are arranged as follows: Round 3 The gameplay proceeds as