Complex sentence: In the season finale, all competitors take part in an extended Circus, which continues until all members of 3 teams have dropped out of the endurance portion, and the remaining members of the fourth team each receive a $250,000 cash prize.
Split into simpler sentences: In the season finale, all competitors take part in an extended Circus. This Circus continues until all members of three teams have dropped out of the endurance portion, and the remaining members of the fourth team each receive a $250,000 cash prize.