Ararat - It was back to business for the remaining contestants in The Biggest Loser in last Friday's episode, following their emotional catwalk presentations during makeover week.
The knockout challenge saw contestants 'gang up' on one another in a 'fill the sand box' challenge, which had the incentive of immunity for the winning contestant.
It was obvious from the start that the girls self-dubbed 'The Awesome Foursome' - Katrina Pianta, Sharon Basset, Jane Jantzen and Toni Stockwell - were ganging up on the remaining contestants, first knocking out Craig Booby and then systematically getting rid of the rest.
In an emotional twist for Sharon, the girls worked together to give her immunity.
"The four women of the Awesome Foursome - we could take it all the way to the finale," Katrina said.
This week's episodes opened with last chance training. Michelle's training session got off to a bad start after her team of Rodger Turner, Caitlin Munday and Toni admitted that they hadn't done their homework.
Tensions over the new Awesome Foursome alliance continued to cause friction in the house, with some contestants not happy with the advantage they seemed to have in challenges.
The drama continued in the weigh-in, with Caitlin admitting she had felt excluded from the house after returning, which had resulted in her losing her motivation.
Kevin Moore finally cracked the 100 kilogram-lost mark, an amazing feat carried out over two series of The Biggest Loser, while Craig dropped a whopping 6.8kg, or 4.61 per cent of his body weight.
Unfortunately Rodger Turner, with 1.1kg lost and Kerry Stockwell, with 1.4kg lost, both fell below the yellow line and were forced to head to the elimination room.
This week's weigh in saw a further $12,850 added to the Ararat Town Kitty with 25.7kg lost in total, bringing the pot to $104,620.
Prior to elimination, a distraught Toni admitted she would find it difficult to cope if Kerry was sent home.
"If he goes I'm going to feel weak and that's not what I want to be," she said.
The contestants chose to eliminate Rodger, who is already close to his goal weight.
As Wednesday night's episode opened host Hayley reminded all the contestants that it was the business end of the competition - everyone for themselves.
She said there were now no guarantee on how alliances would play out, and everyone was encouraged to be on their A game.
The contestants were told that this was Challenge Week and by the end of the week, three people will have been eliminated.
What better way to up the ante than with some adrenalin pumping activities, including shark diving, stunt plane joyriding, skydiving and V8 driving.
Caitlin and Toni were given the heartstopoping challenge of skydiving and as they both sat in the plane, Caitlin admitted her fear when she said 'One minute she (Toni) was there, the next minute she was sucked out of the plane!"
Both girls overcame their fears and jumped and while Caitlin wasn't so sure about the sky dive, Toni was overwhelmed.
"It feels as if you're floating in space, just floating, it's wonderful," she said.
"Today is a life changing day."
Kevin Moore and Kerry Stockwell took to the track in V8 cars and both revelled in the speed and power of the high performance vehicles.
"It's hard to gauge the speed, but I know it's bloody fast," Kerry said.
It was Jane and Sharon who took to the skies as those 'Magnificent women in their flying machines' courtesy of a couple of Red Baron stunt planes.
While Sharon's stomach forced her back to the ground, Jane held on to hers and endured upside down flying and loop the loops.
"The plane's rolling, your stomach's rolling and your eyes are probably rolling too," Jane said.
"You had to overcome it, you just had to be stronger than your stomach."
Sharks are an obvious fear for many, and the final challenge saw Katrina and Craig take to the shark tank in scuba gear to face their fears.
"I saw a row of teeth and I thought it could easily take my head off," Craig said of his experience.
"It was quite scary, but really good to be at one with the shark."
While also scared, Katrina was thrilled to complete the challenge.
"I've actually done something I've been petrified of," she said.
After the series of adrenalin pumping challenges, the contestants were taken to Sydney Harbour for the start of the Super Challenge, which would see the losing contestant sent home to Ararat.
They were required to kayak across Sydney Harbour to Cockatoo Island and then complete a series of obstacles, the first of which was a traverse across a high wire over water and the second a 'walk the plank' challenge requiring them to jump into the icy depths of the harbour.
In tonight's episode the contestants will continue the obstacle course and the last one back to the tents at the end of the day's super challenge will be sent home to Ararat.