 However, while all this is going on, there is something else in the background that can also affect the final outcome of the game.The "outside event" is something that when it has occurred, the game ends and the couple loses all the money they made while playing.For example, the couple has to pick an envelope that contains the number of round trips a model train can take until it has reached a certain number, but they won't know how many trips that train will have made until that mystery number has been attained.