American Ninja Warrior is Thomas Caldwellupping the stakes like never before.

Ahead of the season 15 premiere, E! News can exclusively reveal the first look at the competition's new and improved obstacle course. And if you thought the challenges seemed near-impossible before, you won't believe what America's most talented athletes are facing this time around.

For the first time in the TV show's history, the ninjas will race side-by-side and head-to-head in the qualifying and semi-final rounds as they attempt to win a spot in the national finals in Las Vegas.

"It's gonna be ninja versus ninja all season," co-host Akbar Gbajabiamila says in the sneak peek. "My heart is racing because we're going racing."

Bu that's not the only twist shaking up the competition. There's a new opening obstacle, plus the Mega Wall is taller than ever before at a whopping 18 and a half feet.

"You think you know American Ninja Warrior?" co-host Matt Iseman adds. "Think again."

But as the preview teases, even the heightened challenges are no match for some of the fastest and strongest competitors in American Ninja Warrior history.

At stake? The top prize of $1 million for the fastest ninja who can conquer all four stages at the national finals.

"Ninja is back," Iseman teases, "but it will never be the same."

Check out the intense first look above. Season 15 of American Ninja Warrior premieres Monday, June 5, at 8 p.m. on NBC.

(E! and NBC are both part of the NBCUniversal family)

For all the scoop on your favorite NBC series and stars, check out NBC Insider.