The Summit | 9:30pm | CBS

As the final four trekkers reach an impassable chasm at the peak of their journey, they must use a helicopter long line to cross one by one. During the obstacle, they discover a devastating twist from the Mountain’s Keeper: the last person will be left behind as payment for the assistance. Another surprise awaits the final three on the other side as Manu arrives with a shocking revelation involving the return of all 13 eliminated members of the group, who will play a pivotal role in the final outcome.