Scott Speedman knows something about survival mode. He and his partner welcomed their second child just over a month ago and, well, he’s familiar with getting through the days on little sleep.

“My kid’s not sleeping at all, so I drive him around from like, 12:30 to 2:30 in the morning,” he says. “I’ve lived in Silver Lake for 21 years now. I was there in my 20s and early 30s, and did all the bars and clubs. It’s hilarious to now have this kid in the back [of the car] while the clubs are getting out; to go by the Cha Cha Lounge and all these bars that are just flooded with kids while I’ve got the lullaby music mix on Spotify going.”

Still, midnight drives with a wakeful infant aren’t quite the same test he faces in his latest TV role. In “Teacup,” he has on his shoulders the weight of saving his family and neighbors — and, possibly, humanity — from a mysterious threat.

Speedman and Yvonne Strahovski star as James and Maggie Chenoweth, a couple living on an isolated ranch in Georgia with their teenage daughter, Meryl, young son, Arlo, and James’ mother, Ellen. As Maggie and James navigate a troubled patch in their marriage, they must confront a bigger danger to their family when Arlo goes missing in a nearby forest and, soon after his eerie return, a mysterious man in a gas mask shows up and spray paints a blue line around the farm, warning everyone within not to cross it — or trust anyone.

A horror series on the surface that’s powered by the family drama underneath, “Teacup” is loosely adapted from Robert McCammon’s 1988 novel “Stinger” by first-time showrunner Ian McCulloch (“Yellowstone”) and is produced by well-known horror filmmaker James Wan (“Insidious,” “Saw”). The first two episodes of the series are available to stream on Peacock, with two episodes releasing weekly until its finale on Halloween. It’s already received a stamp of approval from frightmaster Stephen King.

Boris McGiver, left, and Scott Speedman in “Teacup.”

(Mark Hill / Peacock)

It’s the sort of premise that lends itself to “What if?” questions. Like, what would Speedman do if a person in a gas mask showed up now and delivered the same warning? We’re on the seventh floor of a newly renovated building on the NBCUniversal lot in Universal City, about seven miles from his family and his home base — and he’s sitting opposite a reporter who is certain the adrenaline would cause her to tap out rather than kick her into action. Speedman scans the perimeter as he considers his options and quickly quells any potential for this fictional L.A. spinoff.

“I would be dead,” he says with a laugh. “I would have ran over the blue line. It’s the first thing I would have done.”

More seriously, though, he says the moments in “Teacup” in which the Chenoweths’ children are in jeopardy, and James is left to make sense of the danger without outside help, were more emotionally challenging to shoot than he expected. Although he’s played dads before, it hits different after becoming a real-life parent.

“Now, having kids, I’m like, I need to go back and redo whole performances,” he says. “When you have kids, something else kicks in, some part of your brain kicks in, and all you care about is that you want to do whatever it takes to protect them. Being a parent is scary; the best comparison I could give is, if you’re in a grocery store and you look behind you and you don’t see [your kid] for two seconds, that’s the scariest thing. What James faces is that times 100. We had to do complicated stuff and there were big discussions about parenting and what would I do in these situations that are never gonna happen in real life. In a situation of having hope versus no hope, you choose hope.”

In “Teacup,” Scott Speedman plays a flawed family man who is trying to keep his family safe from a mysterious threat: “This idea of not trusting anyone that’s central to the story, that starts with my character after what he’s done to his family,” he says.

(Marcus Ubungen / Los Angeles Times)

Comfortably seated on a couch, Speedman, 49, is soft-spoken but upbeat, like when he admits the only TV he’s consuming these days is “Peppa Pig,” thanks to his nearly 3-year-old daughter, Pfeiffer. (“My daughter has a British accent because of Peppa,” he says. “But she doesn’t watch it, she listens to it. We try not to let her watch too much.”) At a casual mention of the generation(s) of teen drama enthusiasts giddy about the simultaneous return of Josh Jackson, Adam Brody and now Speedman to their TV screens at the same time, he cocks an eyebrow and wonders about the intensity of the nostalgia factor: “Is that, like, a ’90s thing?”

Since his breakout role as Ben Covington, the brooding heartthrob of late-’90s coming-of-age drama “Felicity” who could make “hey” sound like a 10-page love letter, Speedman has distanced himself from the character. He’s played Michael Corvin, the vampire-werewolf hyrbid in the “Underworld” film series; Barry “Baz” Blackwall, a member of a dysfunctional Southern California crime family, in “Animal Kingdom”; a U.S. navy officer in “Last Resort”; and Matthew Engler, a wealthy tech CEO who becomes consumed with finding out the truth about his wife’s death in “You.”

In addition to “Teacup,” he stars alongside Jordana Brewster in the upcoming thriller “Cellar Door,” where they play a couple who relocate to the Portland, Ore., suburbs and discover their dream home is a nightmare. He’ll also reprise his role as Nick Marsh, the transplant surgeon and on-again, off-again boyfriend of Meredith Grey (Ellen Pompeo) in “Grey’s Anatomy,” for several episodes this season.

“I’ve thought about this a lot and there was nothing that led to this at all in my upbringing,” he says.

Speedman was born in London; his parents moved the family to a suburb of Toronto when he was 4 years old. The family was steeped in athletics: His parents met at a track meet in Scotland when they were teenagers. (“My mom, to be fair, was locally a more famous runner at that time and and I think there were three suitors who wrote letters to her, and his was the best letter.”) From an early age, Speedman took an interest in swimming; he attended Earl Haig High School, which had special programs for gifted athletes and artists. As a competitive swimmer, he ranked well at the 1992 Olympic trials, but he suffered a neck injury when he was about 16 that dashed those dreams.

“My Olympics would have been eight years later — probably, if I had continued or whatever,” he catches himself. “But it didn’t happen. I liked training. I liked going to the pool every day. I still, to this day, need to do all that. But that school was probably the luckiest thing that happened to me because being in that environment with performers caught my interest.

“I would go watch these kids do their one-act plays,” he continues, “and I was extremely shy, not an extroverted kid, so something about it just pulled me in.”

He began working with an acting teacher in Toronto, becoming obsessive about movies, and found his way into auditioning very quickly. He went on “Speaker’s Corner,” a video forum for Torontonians that aired on MuchMusic, the country’s version of MTV, as a way to get to the attention of the casting agent for “Batman Forever.”

“You put in $1 at this booth and it filmed you talking about anything you want to talk about,” he recalls. “And I said I knew she was in town doing these casting calls. She saw that and called my family home and invited me down to audition. I had a couple callbacks, but I obviously didn’t get it.” (The role went to Chris O’Donnell.)

After some time acting in small roles in Toronto, Speedman went to theater school at the Neighborhood Playhouse in New York City but dropped out. While living on his mom’s couch, a casting director called after looking his name up in a phone book. They sent him a TV script, but he had no interest in it. A Canadian agent heard Speedman said no to an audition and told him to reconsider. He sent in a videotape and was quickly cast. The series was “Felicity.”

And although the show premiered before the rise of social media, Speedman says being part of the WB bubble of that era was intense.

“I was unable to really connect to what that is,” he says. “It was challenging. I sent a videotape audition and three days later, I was filming the show. They rented me an apartment and I had to go to school for a bit until they got me into the country legally. It was just very tumultuous being 22 and experiencing that kind of culture shock. I thought I was just gonna be an actor in Toronto at that time.”

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1. Scott Speedman, left, and Ellen Pompeo in “Grey’s Anatomy.” (Liliane Lathan / ABC) 2. Scott Speedman, left, and Keri Russell in “Felicity.” (TLP)

More than two decades since the series finale, he’s aware that fans still hold onto that image of him. “Where I am now is just so different than where I was,” he says.

But there’s no denying that his former alter ego Ben Covington inflects his current roles, especially on “Grey’s Anatomy.” Finding a love interest for Meredith Grey who could measure up to her great love, Derek Shepherd (Patrick Dempsey), who died nearly 10 years ago on ABC’s long-running medical drama, required someone with the gravitas of a leading man.

“I gotta tell you, I was team Ben all the way,” says Meg Marinis, the current showrunner of “Grey’s Anatomy,” who was a writer when Speedman’s character was introduced. “I was so excited because ever since we lost the character of Derek, we were thinking about, ‘What leading man can challenge Meredith and break her open a little bit?’ And when I heard that Scott had been cast in the role of Nick, I was like, ‘Well, there you go. We have it.’”

For Speedman, trying to earn the admiration of the audience required thick skin: “When I first came on that show, there was a lot of comparisons; people not into it. It was honestly kind of funny to me. It doesn’t bother me. Some of the things that have been freeing to me is getting bad reviews because it weirdly lets your shoulders drop a little bit. It really does. I think earlier in my career, that kind of fan reaction would have wrecked me. At this point, it’s like, ‘Yeah, I get it. [Derek’s] awesome, but he’s dead. We can only bring him back so many times in a dream.”

Scott Speedman, who stars in the upcoming Peacock horror series “Teacup,” poses for a photo on the NBCUniversal lot.

(Marcus Ubungen / Los Angeles Times)

In “Teacup,” the “Felicity” card may help as well, as viewers learn early on that Speedman’s character, who is supposed to be the patriarchal hero in the tale, has cheated on his wife.

“This idea of not trusting anyone that’s central to the story, that starts with my character after what he’s done to his family,” Speedman says. “As the assassin game goes on, we do need each other to survive. The family stuff, more than anything, is what I was interested in.”

“Teacup” showrunner McCulloch says of Speedman: “He’s swimming upstream and it’s a very rapid current away from empathy with the audience for his character. By the end of the season, he’s got a great redemption arc that really spoke to him and spoke to me because the idea that characters need to be likable, it’s a fine line, but they give him something to do other than be a white knight. Grounding this [story] in the real world, in the naturalistic world, it felt like we needed to have characters that have real-world problems, real-world flaws. And if you’re going to have somebody who’s done something that hurt people, it doesn’t hurt to have Scott Speedman be the face of that, because he’s just stupid handsome.”

Speedman is not done working his creative muscles. He and McCulloch also have collaborated on a film script that they hope to bring to fruition soon. Until then, he’s curious to see how people respond to “Teacup.” And he reconsiders how he’d react if he were in James’ shoes.

“I think I’d be a leader,” he says. “This could be all just bull—. I could be hiding. I have no idea. But I want to believe if something goes wrong, that I’d take charge. I guess you don’t really know until it happens.”