The teams switch trainers in a move designed to get them out of their comfort zones. Elsewhere, one trainer tries ballet; and the teams navigate a mud pit to locate weight plates in a messy challenge

The contestants go home for 18 days and have a chance to earn immunity if they lose five percent of their body weight. While some struggle to stay on track, others benefit from the support of family and friends. Also: a home rowing challenge earns the winner $10,000.

A temptation-challenge winner reorganizes the teams in an unpopular move that creates tension and suspicion among the players. Elsewhere, the teams race to assemble a large puzzle in order to win a special prize

Two players visit home with their trainers in tow, and their weights alone count at the weigh-in. Elsewhere, the teams compete in an obstacle course in order to receive letters from loved ones for Valentine’s Day; the players at the ranch must fend for themselves, though one contestant turns to nutritionist Rachel Beller for help [...]

One team must work out for a week without the guidance of their trainer, who secretly monitors his players to track their progress. The losing team is determined by a dunk-tank challenge, in which Bob and Dolvett are suspended over water and must rely on the contestants to keep them dry.

The teams bet on the percentage of weight they think they’ll lose in order to gain an advantage at the weigh-in. Elsewhere, the contestants learn to shop for healthful foods; the teams compete in a puzzle-based challenge; and Dr. Huizenga performs sobering health assessments

The winner of the $250,000 prize is crowned in the Season 12 finale. The eliminated players also return to weigh in for the $100,000 at-home prize

The eliminated players return to run a marathon, and the winner earns a spot as a finalist. The first five players to finish also receive a share of a $50,000 prize. Later, the contestants weigh in to determine which two move on to compete in the finals

The five remaining players receive makeovers with help from stylist Jeannie Mai and hairdresser Ken Paves. Later, they show off their new looks to family and friends before attending Cirque du Soleil’s “Iris.”

Updates on past contestants are presented, along with bloopers and behind-the-scenes footage. Also: The trainers offer their thoughts on the current season; a contestant makes a surprise announcement; cameras follow Bob through an average day; Aida Mollenkamp prepares a diet-friendly Thanksgiving dinner and offers cooking tips.