Note: This story contains spoilers from “Countdown” Episodes 1-3.
In the Prime Video action thriller series “Countdown,” Jensen Ackles’ undercover cop is pulled out of prison for a top-secret investigation that could spell doom for all of Los Angeles. A case that starts off with the murder of a Homeland Security Agent escalates into the threat of a nuclear strike, and the team has no idea who they can trust within law enforcement.
Ackles described the series from creator Derek Haas as “a really fast roller coaster ride from tip to stern.” And after his previous series “Supernatural” and “The Boys,” he told TheWrap he enjoyed playing in the real world for once. “There’s no superheroes or demons. You couldn’t make a deal with the devil to come back from death. You couldn’t take off and you couldn’t laser-eye somebody,” he quipped.
In the first three episodes, which premiered on Prime Video on Wednesday, we also find out that, unbeknownst to the rest of the team, his character, Mark Meachum, has an inoperable brain tumor.
“It was a lot of fun to be able to play with real-world consequences knowing that if you’ve got a brain tumor, OK, well, there’s no fixing that. This is life and death, and this is the real world. The stakes were a little higher,” he said.
Look below for more with Ackles on the first three episodes and what’s ahead.
TheWrap: How is Mark having an inoperable brain tumor going to play out over the season?
Yeah, this is something my character is hiding from not only his team, but from his commanding officer. You see Oliveira (Jessica Camacho) say in the trailer, “You’re acting like you’ve got a death wish.” And it’s not that he has a death wish, it’s that he knows he’s dying and he doesn’t care if he dies. So he’s going to throw his body on the grenade, which is really fun for me to play. He’s going to go in guns blazing and he doesn’t care if he comes out alive.
But it really sets the team off in a way of like, can we trust this guy? Is he crazy? Is he going to go off the rails and do something that we can’t come back from? It’s a testament to Derek’s writing, him putting this ticking time bomb within a scenario of a ticking time bomb.
You get this fantastic first scene in the prison exercise yard where you take out two other prisoners with a huge barbell.
When I read that, I got excited. Here was the bad part. That was the very first day of filming. It was the first week of September in Palmdale, California, in the middle of the desert. I think it topped out at 115 degrees. We had no shade. It was a decommissioned prison, so it was an actual prison yard and we had a massive fight scene in the middle of the day. We literally waited until the sun was right at 12 o’clock. The dirt was just caked onto our faces because we were like, sopping in sweat. It was one of the filthiest, grossest days. I turned to the crew, and I was like, “It can only get better from here.”
Is it your first screen fight using a barbell as defense?
They pitched that. They were like, “OK, you’re going to slide the weight off into one guy’s foot.” And I was like, “OK, guys, all right, I see what we’re doing here. This is fun. Let’s go.”
The show is kind of like “24,” but more fun.
That’s a good assessment. Yeah, “24” is definitely a comparison that’s been kicked around quite a bit. And it has a little bit of that Lethal Weapon aspect to it. But there is an urgency to the situation, more than any other cop drama they’re dealing with case after case after case after case.
This is one case that starts to unfold into something bigger and larger and more detrimental. The stakes keep raising themselves with each episode. It has an intensity to it that you don’t see as much on other shows. Maybe they have an episode that’s really intense, but this feels like a really fast roller coaster ride from tip to stern.

And Mark starts things off by hitting on the one woman in the team, played by Jessica Camacho.
[Laughs] He probably thinks he has more game than he actually does. The obvious answer is he sees an attractive woman. And maybe it’s not just hitting on her, maybe it’s sizing her up. I wanted to play both, because you want to try to find a foundation of the will they or won’t they.
But that was more of a test of like, “Who is this person and can I charm her?” Because if I can charm her, then somebody else can charm her and that’s not good. I need to know that I can trust these people. There’s little bits of games that happen within the task force early on, like, Who can I trust and how much can I trust them?
Derek did a great job of setting that in motion with the different characters. And then once they find that trust, then you start unlayering their personal defects, and obviously Mark’s diagnosis is a huge one.
How concerned should we be for your character?
Look, the diagnosis comes early on. He’s not a guy that’s going to go away that easy. If he’s not fighting to save somebody, he might find a way to fight and save himself.
“Countdown” releases new episodes Wednesdays on Prime Video.