SAS Australia gives us a unique glimpse into the secret world of the Special Forces.
For Mark "Billy" Billingham, one of the directional staff on the show, stepping out of the shadows and into the spotlight was more difficult than he could have imagined.
"It's a complete 180 [degree turn] in our lives," Billy, 56, tells TV WEEK.
"I spent half my life trying to get into the Special Forces and, once you're in there, it feels like the rest of your life."
Billy left the Special Forces after 27 years and went on to become a bodyguard for celebrities such as Hollywood A-listers Brad Pitt and Angelina Jolie, thrusting him firmly into the spotlight.
"It was difficult trying to stay in the background when I couldn't," he shares.
"There came a point when I realised that you can't have one foot in and one foot out, so I had to put my head above the parapet and say, 'This is who I am and these are my credentials.'"
While it can appear brutal when Billy and his fellow directional staff are yelling orders in a recruit's face, he promises that the hardcore approach really does have a positive impact.
"When we're screaming on the show, we're actually giving something back [to the recruits]," Billy explains. "Later on, they'll realise certain things we've done and taught them along this process."
After appearing in the UK series of SAS before coming to Australia, Billy has seen the affect the show has had not only on the recruits, but on those watching at home.
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"Everybody has a dark secret or a dark space," he says.
"Generally, we've been there – probably on a worse scale and many times more. We're sharing our experience and how to get through it. The thing is, people at home can relate to us and the recruits.
"We come from a world where purpose is massive. For me, the purpose of doing the show is when you get feedback from people saying, 'You changed my life.'
"As soon as that kicked in, we thought, 'Wow, this is so powerful.'"