A big black bus pulls up in the middle of the desert. The 15 contestants of The Biggest Loser Season 12 get out, wondering what the heck they're doing in the middle of nowhere, as the bus drives away. Suddenly headlights appear on the horizon. It's a tactical Humvee. Alison steps out to welcome everyone to El Mirage, California, which is close to Death Valley and where despite the harshest conditions, new life may emerge. Alison asks the contestants to line up according to the numbers on their shirts, which represent their ages. This season will be a battle for the ages, where anything's possible. Everyone under 30 will make up one team; everyone over 50 will make up the second team; and everyone else is on the third team. Since there are three teams there will be three trainers, two of whom will be brand new.
Just then, several military helicopters dot the horizon. In celebration of 100 years of aviation, the U.S. Marine Corps are arriving with the help these contestants need. Bob runs off the first helicopter, then Anna Kournikova runs out of another. And finally, the third trainer debarks, trainer Dolvett Quince. The trainers climb into three Humvees and drive a mile into the desert, as Alison announces it's time for the first challenge. Each team will hold a pole and race one mile down the desert. The winning team will have their pick of trainers. With all the contestants gunning for Bob, everyone takes off running. Early on, the Seniors realize they won't be first to cross the finish line, especially since 63-year-old teammate Bonnie has a bum knee. They start walking; their strategy - slow and steady wins the race.
The Middle Team begins to overtake the Young Team, who've started walking. Still, they resolve to make it together as a team. Antone cheers the Middles on - they won't be walking when they cross the finish line! With a quarter of a mile to go, Antone wills the Middles across the finish line to pick Bob. They're now the Black Team. Vinnie feels like he can't make it, but the sight of the finish line helps him pull through. Now the Youngs are the Red Team; their trainer, Dolvett. The Seniors are still walking in a line, so Anna grabs the blue flag and runs out to meet her team to make sure they cross the finish line on their first day. Caught up in the spirit, the other teams run out to walk with the seniors. Bob points out that this is what The Biggest Loser is all about: people coming together to prove we are not alone.
Alison explains that while this location is where the contestants took their first steps on the show, it's also where they'll take their last steps. In just a few months, all of them will return, eliminated or not, to compete in one final challenge - a 26.2-mile marathon. Well over 400 pounds, John is sure this is foolish thinking. But as Alison points out, the winner of that marathon will be guaranteed a spot in the finals.
In the morning, the trainers stand in front of the gym, waiting for their new teams to arrive for their first workout. The gym has had a makeover, decorated with huge posters of past contestants. Inspiration! Dolvett stresses breath control, and transforms from nice guy to drill sergeant. Anna tells her team they're going to surprise everyone by leveraging their wisdom and experience. Bob pushes Antone, reminding him that he's an athlete. He should focus on his family to get him through the workout. Johnny's having a particularly hard time. Finally, Anna tells him to leave the gym. His teammates remind him that he's doing this for his nine grandchildren, so Johnny gets back on the treadmill yelling, "I'm not a quitter." When Antone breaks down in tears, Bob asks him if he wants to just quit and wait for death. Antone is now Bob's pet project.
Insisting he wants his team to leave the gym with only enough energy to get back to the house, eat and go to bed, Bob takes them outside for some bear crawling. Again, Antone breaks down, filled with embarrassment. Bob challenges Antone to find his inner strength. His kids need their dad. Antone gets back on his feet and walks back to the gym. Later that night at 3:15 a.m., Becky gets an urgent phone call. Her father has passed away. Unable to sleep, she decides to do something out of character... work out! Even though she's going home for a few days, she now knows she absolutely wants to change her life. The death of Becky's father gives Johnny and the Blue Team a wakeup call; death could be right around the corner for them all. Johnny's words bring Anna to tears, as she realizes that the show is about much more than just losing weight.
Luckily, Becky's back on the ranch in time for the Last Chance Workout, pledging to do everything Anna tells her to do and then some. Anna can't help but get emotional, watching Becky's strength and dedication. Meanwhile, Dolvett focuses on Patrick, whom he believes is deceiving himself. Finally, Dolvett kicks Patrick out of the gym because of his lack of focus. For his part, Patrick knows that he comes across as someone with really good self-esteem, but deep inside he knows he's not. Dolvett advises him that it's time to start believing in himself. With some extra attention from Dolvett, Patrick manages to pull it together. Meanwhile, Antone seems to have made a complete turnaround, from a crying puddle to a fierce competitor who's pushing himself to the edge.
Finally, it's time for Season 12's first official weigh-in. Since this season is the Battle of the Ages, Alison tells the players that tonight will be the first time they'll see if age matters to the scale. It's also the first time everyone will get to see how the new trainers measure up. Bob's confident that age is nothing but a number. The team with the lowest percentage of weight loss will lose the weigh-in, and only the member of that team will be safe from elimination. Earlier in the week, the players established their starting weight. Tonight, the players will weigh in from oldest to youngest, which means at 65 years old, Johnny's up first. His starting weight was 328, and his current weight is 211 for a loss of 17 pounds. Even though he didn't know he could stick it out, Johnny knows he's on the show to stay.
At age 63, nervous wreck Bonnie's up next. She started the show at 254, and her current weight is 250 - she's only lost four pounds, and is very disappointed. Anna tells Bonnie to keep her chin up; despite her bad heel, they'll find a way. Mike started the show at 309 pounds, and now he feels the stress to pull a big number on the scale. He does pretty darn well, with a 12-pound weight loss. Debbie started off at 239 and has lost six pounds. She was hoping for nine, and Anna agrees; Debbie has to find her focus. At 50, Becky is the last Blue Team player to weigh in, and she's nervous since she left the ranch and didn't get to exercise as much as the rest of her team. Everyone's thrilled to see she lost 10 pounds! The Blue Team loses a total of 49 pounds at next is the Black Team, who will have to lose more than 66 pounds, at least 13 pounds per person. Joe's up first. His starting weight was 348, and his current weight is 326 - he lost 22 pounds! Joe's been taking blood pressure meds for over two-and-a-half years - after three days on the ranch, he doesn't need to anymore. The Black Team is a third of the way to beating the Blue Team. Antone's up next, hoping for big numbers. He started the show at a whopping 447 - and he's lost a whopping 32 pounds! Sunny started at 244, and she's lost 16 - the Black Team is definitely safe from elimination with only three players weighed in. John's up next - and he's lost 37 pounds! Jennifer is the last player on the scale, and she loses 19. With a total of 126 for an incredible Bob is thrilled - but how will they be able to keep up these numbers?
The Red Team needs to have lost more than 60 pounds to avoid elimination. At 27, Vinny's first on the scale. He started the show at 426 pounds - now he's down to 405, 21 pounds lighter. Vinny's not too thrilled, so Dolvett advises him to get proud. Ramon's next, and he's lost 17 pounds. Jessica started at 254, and she's managed to lose 15 pounds this week. It's not looking good for the Blue Team as Patrick climbs onto the scale, tearfully admitting it's been a rough week for him. He knows he has a horrible mindset and isn't expecting big numbers. Johnny reminds Patrick that he's tougher than he thinks - and in fact, he's lost 20 pounds! It's a defining moment for Patrick, who actually feels proud of himself and starts trusting Dolvett. Not to mention, the Red Team is safe.
With Courtney's 16-pound loss, the Red Team has lost a total of 89 pounds at Confidence is running high for everyone except the Blue Team, who has to decide who to send home - except for Johnny, who's the team's Biggest Loser. Of course no one wants to go home, and no one wants to vote for any of their fellow team members. Despite her four-pound loss, Bonnie wants to stay. Debbie does too; however, she points out that she has a great support system and a gym membership at home. She goes even further, claiming that Bonnie's constant crying is annoying. Within minutes the two women are arguing about Debbie's insensitive words. Finally Mike ends the argument - it's time to vote.
Becky's first to reveal her vote - for Debbie, who predictably casts her vote for Bonnie. Johnny explains the person he chose went above and beyond; he simply voted for Bonnie based on the amount of weight she lost. Based on what Debbie said about the support she had at home, and prior successful weight loss, Bonnie votes for Debbie. In the end, it all comes down to Mike's vote. Since Debbie had showed so much confidence that she could get it done at home, Mike votes for her. Alison reminds Debbie that she'll be back for the marathon, and may still be a finalist. Despite the fact that she's first to leave the ranch, Debbie realizes her life has changed forever - she's going to come back a jazzy granny, and is still determined to be the last one standing!