On Monday's episode of Fox's 'Special Forces,' Waukesha native and 'Bachelor' star Nick Viall considered leaving for the first time

Warning: Spoilers from Season 2 Episode 5 of "Special Forces: World's Toughest Test" ahead.

On Monday night's episode of Fox's "Special Forces," Nick Viall thought about leaving the show for the first time. But, he pushed through and revealed where his motivation comes from:

Becoming a dad for the first time.

On the show, celebrities take on "grueling challenges from the playbook of the actual Special Forces selection process" while battling the harsh elements of winter in New Zealand, according to Fox. The Directing Staff, made up of an elite team of ex-Special Forces operatives, lead the recruits through the course's demanding training exercises.

Monday's episode marked the midpoint of the course. Seven of the 14 recruits Season 2 started with remained.

"The halfway point is where we really crank the pressure up, because we're essentially trying to emulate war," DS agent Jason Fox, who was formerly a part of the elite Special Boat Services, said on the show. "And, war keeps becoming more stressful, more horrific, more tiring, more exhausting. And, that means there is no room for complacency."

Viall, a Waukesha native and "Bachelor" franchise star, was one of the main characters of Day 5, along with Olympic alpine skiing champion Bode Miller. But not exactly for positive reasons. Viall struggled through Day 5's grueling challenges and the DS wasn't fond of Miller's attitude.

"Probably definitely should not be here," said Viall, host of the popular podcast "The Viall Files." "There's nothing about what I'm doing now that would suggest that I'm going to do well in this type of environment."

With the course taking a physical and mental toll on Viall, here's a look at what he overcame during Day 5:

Nick Viall takes on the 'Commando Cliff Crawl' across a 'deadly ravine'

The recruits were flown by two helicopters to the "most challenging" terrain of the course: A mountain range that was 4,600 feet above sea level. There, they would face the "most demanding" exercise of selection thus far: The "Commando Cliff Crawl."

One at a time, the recruits would lie on their stomachs on a single rope. Using their arms to pull and a leg to push, they would maneuver themselves forward across a "deadly ravine." Partway through, the recruits were commanded to flip upside down and dangle by their arms. Then, they'd have to get back up into their original position.

Viall — referred to as No. 12 by the DS — was last to attempt the test after only two had passed: Miller and "Vanderpump Rules" cast member Tom Sandoval.

"I definitely love to win," Viall said on the show. "I've always been competitive. When I've asked myself, 'What makes me competitive?' Is it like the need for validation? I wanted to see if I can rise to certain occasions. If I can be someone people can count on. I want to make people proud."

Viall glided across the rope, then flipped upside down and dismounted as commanded.

When Viall was told to "get back up," he fought to numerous times. At a couple moments, it looked like he had it. But his hands ended up slipping off the rope and he failed the test.

"You look like a pathetic bag of (beep)," a DS agent yelled.

As punishment for failing, the recruits were dropped off a mile from base. Those who failed the test had to carry the two recruits who passed, along with their bergens.

As Viall carried Sandoval over his shoulder, he continuously groaned out in struggle and had to set Sandoval down multiple times.

"You can learn a lot though your own failures," Viall said in a cutaway. "Life's about trying to overcome them. But, what is it going to be that keeps me from quitting?"

After the halfway point, an exhausted Viall told his comrades he needed help. Siwa carried Sandoval the rest of the way.

'I'm hitting a wall'

When the recruits got back to base, Olympic speed-skating champion Erin Jackson and media personality Jack Osbourne were concerned about Viall.

"What's your name?" Osbourne asked Viall to make sure he was still with it. "Nick" he answered.

"Where are you from?" Osbourne asked. "Wisconsin," Viall replied.

While Viall was recuperating in the dorm, the DS was discussing Viall and determined he had "flagged himself as the weakest."

"He just seems empty," said Billy Billingham, formerly of the British Army's Special Air Service. "He's running on fumes almost."

The DS called Viall in for tactical questioning. When Billingham asked Viall how he was doing, he didn't respond. The DS did not like that.

"I'm hitting a wall," Viall confessed.

He revealed that the past few days had been physically tough on him, and that the course was starting to take a mental toll, too.

When the DS told Viall to tell them something about himself, he said: "I've always tried to do my best. I've always tried to be an over-achiever. I'm a big believer on betting on myself."

The DS were bored by his answer. And, when they asked Viall what he does, they weren't impressed by that either.

"What are you here for?" chief instructor Rudy Reyes, a former recon marine, inquired.

"Recently, right before I showed up, I found out my fiancée was pregnant," Viall said. "So, I want to make sure that people who can count on me can count on me. I want to see what I'm made of."

"You think you're doing that?" Billingham interrupted.

"Yes, staff," Viall replied, getting emotional.

Billingham told Viall that he started off in the middle of the pack, but has been falling back.

"You have the potential to be at the end. I'll tell you that now," Billingham said. "The only person who's going to stop that is you."

"The greatest goal I've ever had in my life was to be a dad," Viall said during a cutaway. "I mean, I really don't know what to expect. I don't know how I'm going to handle it. I don't feel very prepared. Hopefully, this process is getting me ready for what I'm about to experience."

A challenging circuit to finish the day

For the second challenge of the day, the recruits had to do a circuit that included jumping into a wooden tub of water, monkey bars, push-ups, climbing over wooden beams and Burpees.

"No. 12, you are dying," DS agent Jovon “Q” Quarles said to Viall. "If you're done, give me your arm band. You can go home."

Viall didn't do that. At the end of Day 5, none of the seven recruits gave up and left.

The next episode will air at 8 p.m. CT Monday night on Fox.