Here is an excerpt from the instructions. Any wonder I haven't played it ? :
"Provided the Outsider is played before the last trick, the team that played the Outsider keeps it in their trick pile, even though they may have lost the trick to which it was played. If the team playing the Outsider loses the trick the trick will be one card short. To compensate for this, the team that played the Outsider must allow the winner of the trick to choose a random card from their pile. This card is immediately revealed and added to the Winner's trick pile. If this happens and the team that played the Outsider has no trick pile yet, the winner of the trick will be allowed to choose any card from any of the future tricks won by the player who used the Outsider card."