The 18 reality titans from "Big Brother," "Survivor," and "The Amazing Race" are shocked to learn that they are competing amongst six legendary veterans from MTV's "The Challenge"; a new twist puts multiple players at risk at the first elimination.

The challengers battle it out in a difficult water challenge; a new alliance is formed to target a veteran; romance blossoms between two teammates.

The challengers compete in a difficult swimming challenge; a vet turns on one of their own in an act of self-preservation.

A shocking double elimination leaves the challengers scrambling to win a high-stakes, adrenaline filled semitruck challenge to ensure their survival in the game.