It's Halloween at the ranch, and that means a pumpkin challenge and the contestants' first temptation of the season. Off the players go into a field of 100 pumpkins filled with candy treats, cash prizes and a winning ticket giving one lucky player one of the biggest prizes ever awarded in a challenge - immunity for their whole team. Later, one trainer brings a special group of people to work out with his team, while another trainer has a heart-to-heart talk with a contestant about their challenging childhood. "The Biggest Loser" catches up with last season's child ambassador, Biingo, to see how his life - and the lives of his family members - have changed since he was on the show. And later, the players get a motivational boost with coveted letters from home before heading to the weigh-in, where another player is eliminated.

Episode Viewers and Ratings

Season 15 Episode 4 of The Biggest Loser was watched by 6,820,000 viewers, resulting in a 2.10 rating in the 18-49 demographic.

Is The Biggest Loser Renewed or Cancelled for Season 16?

The Biggest Loser Season 15 Episodes...

• s15e01 - Second Chances
• s15e02 - A Game of Chance
• s15e03 - The Auction
• s15e04 - Trick or Treat
• s15e05 - 'The Cook-Off'
• s15e06 - Remember Who You Are
• s15e07 - Thanksgiving
• s15e08 - Take a Trainer Home
• s15e09 - Workplace Obesity
• s15e10 - Down to Singles
• s15e11 - Who Gets a Second Chance Back?
• s15e12 - Winter Olympics
• s15e13 - Makeover Week
• s15e14 - Triathlon
• s15e15 - Season 15 Finale

The Biggest Loser Show Summary

The simple idea of The Biggest Loser, familiar to dieters the world over, is that "whomever loses the most... wins". Losing weight will be difficult, though, as the 12 contestants (six male and six female) will be faced with "real-life temptations" that their new "approved weight-loss skills and resources" should help them overcome - if they want to win, that is.

The twelve contestants will be divided into two teams of six, cleverly named the Blue team and the Red team. The teams will be mixed by gender and will be organized to be approximately equal in weight. Each team will then be assigned a "team trainer" to teach it individual fitness and nutrition regimens. According to NBC, one trainer has a tough 'boot camp' attitude while the other offers a much calmer approach yet remains strict and focused on results. So ... will the carrot or the stick work better?

The personal fitness trainers on The Biggest Loser will be Jillian Michaels and Bob Harper. Michaels' celebrity clientele includes entertainment mogul David Geffen, Amanda Peet, Vanessa Marcil, Amber Tamblyn, Sarah Paulson and Jeremy Renner. Harper is a consultant to trainers and teachers alike, and has trained such celebrities as Gwyneth Paltrow, Ben Stiller, Ellen DeGeneres, Melissa Etheridge, Guy Ritchie, Lauren Dern, Selma Blair, Jessica Alba and Dermot Mulroney.

To be sure that the contestants do not drop dead on the air from all the unaccustomed exercise, they will be under the supervision of off-camera medical experts, including Robert Huizenga, author of "You're OK, It's Just a Bruise", the book on which the feature film Any Given Sunday was based, and UCLA nutrition professor Dave Heber.

During each week's broadcast, the teams will face difficult and demanding daily work-outs culminating in a weekly competition in the form of a challenge, but the moment of truth will come during a weekly weigh-in. At the weigh-in, each team member will be weighed to determine the total pounds lost as a team. The team that loses the least amount of weight is faced with having to eliminate one of their own. In the end, the winner of The Biggest Loser walks away with $250,000 and a healthier body augmented by new coping skills.