With its third season, Apple TV+’s spy drama “Slow Horses,” based on Mick Herron‘s series of spy novels, doles out the smallest revelations about Jackson Lamb, the head of Slough House, played by Gary Oldman.

“Another layer of the onion is peeled back,” says Oldman, whose Lamb doesn’t mind that the world sees him as a slovenly, flatulent insult hurler leading a team of failed operatives. Of course, he’s more complex than that. “There’s also a great moral compass, it’s very strong, and there’s loyalty too. Even though he might be a taskmaster, he’s very loyal to his team.”

The series received nine Emmy nominations, including a lead actor in a drama nod for Oldman.

Explain one of Jackson’s superpowers: He’s a human databank when it comes to his MI5 rejects. How is that?

That’s the spycraft. He knows where everybody lives. [He’s] followed them. He knows what they’re up to. That’s what I think is great about the spycraft of Lamb. It’s the clothes, it’s all that; you keep people guessing. In Season 4, we have a new head of the security department at MI5. She thinks she’s got his number immediately and completely underestimates him. The idea behind the dirty [raincoat] and the smell of whiskey and cigarettes is that he’s playing chess. That’s one of the great joys of playing him. That and the fact that he has no filter, that he’s utterly direct. The reason we enjoy it as an audience, and I enjoy playing it, is because we can’t be like that in our lives. And on top of it, we give you James Bond, but warts and all, with dirty laundry and stale toast.

Would James Bond casually assemble an intruder alarm, as Lamb does, out of nails, a knife and a can of Pringles?

That’s the thing: With moments like that, you see the years of experience. It’d be easy to brush him off. “He doesn’t care very much. He drinks too much. Not very healthy. Smokes too much.” All of those outward things. I mean, he immediately comes through the door and goes straight to the sandwiches. “Oh, is this ham?” I love that. It’s quirky. Then come the moments where he can choreograph that intruder alarm. I think it’s so unusual. I love that we live in a “Slow Horses” world where John le Carré and James Bond [are mentioned]. David Cartwright [Jonathan Pryce] can reference John le Carré, and Lamb can say, “He’s got this poison thing like he’s [Bond arch villain] Rosa f— Klebb.” I love that about the show.

You’ve said you’d be happy to do “Slow Horses” for the rest of your career.

“I’m a fan of long-form TV. I love being in these different worlds, with these different characters every week,” Gary Oldman says.

(Apple TV+)

I’m a fan of long-form TV. I love being in these different worlds, with these different characters every week. Sometimes I’d watch with envy and think, “Wouldn’t it be great to be a recurring character who intersects with the same people, rather like a theater company, where you keep coming back and developing these stories and characters?” Plus the writing, cinematography, acting, set design! I mean, it’s better than anything you’d see on the big screen.

After an excruciating amount of time spent in the “Darkest Hour” makeup chair to play Winston Churchill, did you set out to find a role like Jackson Lamb where you just put on dirty clothes, a stained overcoat and you’re camera-ready?

Here’s the story: I said to [my producing partner] Doug Urbanski, “Here’s my bucket list: I’d like to not use an accent or wear a wig. I don’t want prosthetic makeup. I don’t want a huge amount of costume changes. Preferably, it’d be well written and in the world of espionage.” Then I sort of said, “Now go find it.” A short time later, I’m sitting on a plane with Doug, and he’s reading. I leaned over, and said, “What are you looking at?” And he said, “A character who’s about to become your best friend.” When it was presented to me, I went, “I’ve got, like, one costume? It’s espionage and it’s in England? I don’t have to do an accent?” I couldn’t believe it. It ticked every single box. And on top of that, it was really good.

Season 5 is already wrapped. Any evolving theories on Jackson and his windy digestive problems?

In Season 5, we’ve got an absolute zinger. [Laughs] The scene is about my flatulence. It’s a great one. We had such fun shooting it. He says, “It’s just gas, the most natural thing in the world. Don’t know what everybody’s so excited about.” But I actually think he uses it like, “Don’t get so close to me.” Literally. He’s delicious that way.

Jackson seems to always be eating. Do you think he’s a secret epicure?

He knows the places that you could hit quickly, because it’s that working lunch thing, isn’t it? He’s always on the run. I think he’s just shoveling it in. But given the food that he eats, I think it’s probably the best quality of that particular type of food. He would know where to get a really, really good sausage roll.