Jensen Ackles is set to lead a new action-thriller series at Amazon Prime Video from “One Chicago” alum Derek Haas, Variety has learned.

Titled “Countdown,” the official logline states the show begins “following a suspicious murder in broad daylight, which leads to LAPD officer Mark Meachum (Ackles) being recruited to join a secret task force of undercover agents from all branches of law enforcement to investigate. But as the truth of a more sinister plot comes into focus, the team must overcome their conflicting personal agendas to unite and save a city of millions.”

Amazon has given the show a 13-episode order. Haas created the series and serves as executive producer and showrunner. The series is produced by Amazon MGM Studios. Ackles and his wife Daneel’s production company, Chaos Machine, is currently under a first-look deal at Amazon MGM studios, while Haas is now under an overall deal at the studio. “Countdown” was developed as a starring vehicle for Ackles, who previously collaborated with Amazon with his role as Soldier Boy in the hit series “The Boys.”

“I had an incredible experience working with the Prime Video team on ‘The Boys’ and am delighted to be able to continue that relationship on Countdown,” said Ackles. “I simply cannot wait to partner with Derek and the rest of our ‘Countdown’ family to bring this story to life.”

This marks one of Ackles’ first TV starring role since the end of “Supernatural,” the WB/CW series on which he starred with Jared Padalecki for 15 seasons. The show wrapped up its historic run in 2020. He also starred in the third season of the ABC drama “Big Sky.” He also executive produced and narrated the “Supernatural” prequel series “The Winchesters” at The CW. Most recently, Ackles appeared in “The Boys” and its spinoff series, “Gen V,” as well as making a guest appearance on the hit CBS show “Tracker.”

He is repped by Gersh and Johnson Shapiro Slewett & Kole.

“I am thrilled to be working again with Jen Salke and Vernon Sanders and all the excellent people they’ve assembled at Prime Video,” Haas said. “I love making shows that keep you on the edge of your seat with nonstop action, drama, surprises, and suspense, and I can’t wait to work with Jensen and for everyone to see ‘Countdown.’”

Haas is perhaps best known for his work in the Dick Wolf universe, specifically launching the shows “Chicago Fire,” “Chicago Med,” and “Chicago PD” at NBC. Haas co-created “Chicago Fire” and served as co-showrunner for more than a decade while also executive producing the other two shows. He then co-created “FBI: International” with Wolf and served as showrunner for two seasons. He is currently an executive producer on the Amazon series “On Call,” which hails from Wolf Entertainemtn. Haas also co-wrote several hit films, including “3:10 to Yuma,” “Wanted,” and “2 Fast 2 Furious,” and has written multiple novels, including “The Silver Bear” series.

He is repped by UTA and Hansen Jacobson.

“We are incredibly excited to be back in business with Derek Haas,” said Vernon Sanders, head of television for Amazon MGM Studios. “He has an undeniable ability to enthrall audiences with thrilling storytelling and heart. We cannot wait for Prime Video’s global customers to experience this dynamic series, led by our very talented star, Jensen Ackles.”