The final nine contestants are delighted to learn from host Alison Sweeney that the game is now going to singles and they'll all compete as individuals for the rest of the competition. Then she reveals a big surprise - the eliminated contestants have returned to try and win a spot back in the game. But for the first time in Biggest Loser history, the player chosen won't be determined by weight loss, but rather by popular vote. After that contestant is voted in, the remaining eliminated players get to battle it out for another spot back in the game - going to whoever wins a 1,000 step-ups challenge. Later, a close friendship starts to unravel, and after a tense weigh-in, another contestant is sent home.

The competition heats up when the players learn that whoever loses 2% of their body weight first this week gets immunity. The catch is that only one person gets immunity and they only get one shot to weigh in whenever they think they've reached that goal. Later, the players head to the pool for a swimming challenge involving weights. After each contestant finishes the race, they are allowed to go back and help others finish, which proves very revealing about who the players want to stay in the game -- and who they don't.

This week's pop challenge finds the contestants piling quarters, each worth $10, on to platters, and then trying to balance the platters as long as they can to win the money they're holding. Aftwards, financial expert Suze Orman talks with the contestants about their financial health, along with season 8 winner Danny Cahill, who she predicted would win last season. It's a wake-up call for many of them struggling with their personal finances, especially when Orman shares her prediction for who will win this season. Then a wild challenge in the pouring rain finds contestants racing to find the right keys that will open this season's biggest prize yet for two lucky contestants - brand new cars! Later, trainer Bob Harper takes the players outside for a workout in the mud, which leads to a wild mud-wrestling fight and a lively chase to bring trainer Jillian Michaels into the fray.