The 18 reality titans from "Big Brother," "Survivor," and "The Amazing Race" are shocked to learn that they are competing against six 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.

"The Challenge" vets come up with a plan to take advantage of a growing rift among the rookies, resulting in one of the most shocking hopper results of the season.

Things get heated between two rookie players; the competitors brace themselves for host TJ Lavin's favorite challenge of the season, trivia.

A pair of "Challenge" vets play cupid as romance blossoms for a couple of former "Bog Brother" houseguests; TJ makes a shocking announcement that impacts the game for the remainder of the season.

The game takes a dramatic turn when TJ announces that teams are no more, strategy shifts for several players, and a draw from the hopper forces two ride-or-die allies to go head-to-head in one of the most grueling eliminations yet.

Michaela sets her sights on a fellow "Survivor" player who could be a threat to her game.

With the news of another double elimination, the remaining players grapple with tough decisions: betraying friendships or risking elimination. The Survivors navigate the departure of a valued member, and the loss of trust in another.

Michaela's sudden decision to target a fellow alliance member leaves Chanelle and Desi to question if she has their best interests at heart; Michele finds herself in the middle between two alliances, ultimately betraying one of them.

When an unexpected winner emerges from the challenge ruins, tables are turned and all alliances scramble to navigate this new power dynamic. Tempers flare and lines are drawn for against one player after a last minute voting decision.

With the final close, one player must face their fear in a terrifying challenge. Then, a double elimination forces allies to turn on each other and leads one player to consider a shocking betrayal before the most brutal elimination yet.

The final 8 competitors battle in a 2-day challenge where a man and woman will be crowned champions and split the $500,000 grand prize.