SPOILER ALERT: Do not read if you have not yet watched “Pizza,” the third episode of “Servant” Season 2, streaming now on Apple TV Plus.

Recently Lauren Ambrose showed her teenage son “The Sixth Sense,” M. Night Shyamalan’s 1999 film about a young boy who sees dead people and the man who thinks he is supposed to help him, only to realize he is the one who needs help. Watching the film now, while working on Shyamalan’s psychological horror series “Servant” for Apple TV Plus, gave her new perspective on both the overall genre and her individual show.

“That is a person who is desperately refusing to accept his own mortality, and it’s what we’re all doing at times. And [‘Servant’] is a version of that,” she says of the two projects. “Buddhists say, ‘One loss is all loss,’ and so this family that refuses to grieve and this mother that refuses to let this ultimate horror — this ultimate vulnerability — in is the story of this show, which is such a human thing, but we take it in this dark, funny, absurd, scary extreme way.”

In “Servant” Ambrose plays Dorothy Turner, a reporter, wife and mother, who tragically lost her infant son Jericho when she left him in a car for hours on end. His death was so traumatic for her that she refused to acknowledge it, which led her husband Sean (Toby Kebbell) to purchase a reborn doll. The couple even went as far as to hire a nanny (Leanne, played by Nell Tiger Free) for the doll. At the end of the first season, Dorothy picked up the doll from its crib and finally saw it for what it was, but rather than have the memory of what really happened to Jericho flood her psyche, she believed Leanne ran off with her still-alive son, which leads her, in the second season, to go to “some crazy lengths to get her child back,” Ambrose says. “She will really stop at nothing. She’s fueled by maternal rage.”

One of Dorothy’s early tactics is to turn back up at her news station and deliver a pointed and uncomfortable on-camera plea to Leanne, who she treats as a missing child.

“She’s stuck in a persona that she presents to the outside world and nothing is going to hammer away at that. But things do, over the course of the second season,” Ambrose says.

This plea is a slight slip of the mask she wears when she is in “performance” mode as a reporter — and for it, Ambrose shares she was thinking about her own children, as well as the way you might talk to a “baby or animals — like talking to a a kitty cat who’s under the sofa.”

The level of intensity Dorothy delivers only ramps up from there, culminating in her drugging a pizza Leanne ordered from Dorothy and Sean’s impromptu take-out company (which they created just to get to Leanne in the first place) in the third episode of the second season. As Dorothy tells her husband, she “handled” the situation, which puts the character in more control than the first season, when both Sean and her brother Julian (Rupert Grint) were “weaving a web of lies” and “think she’s so fragile,” Ambrose notes.

Although Dorothy is still suppressing a lot of painful truths, she is exhibiting a special kind of strength — one that she adopted early on in her journey of motherhood, as evidenced in flashback scenes showcasing her drive to save her son (and herself) when her kitchen caught fire while she was supposed to be on bed rest.

“She was a fierce mother from the beginning. She has this drive to protect her child, and she wanted this baby so badly that to have it ripped away in this way that she would feel is her fault, even though we explore how everyone in this family is at fault and it’s also an unexplainable thing. She’s the type of personality who would see it as just a failure,” Ambrose says. “In the playing of the [flashback] scenes, I found my way back to being sympathetic towards her because she just has every horror that a mother could possibly experience. She’s dealing with it in such a flawed way but [with] all of the vulnerability of being a parent [and] a human being.”

With Leanne incapacitated at the end of the third episode, she can be brought back to Dorothy and Sean’s home, only now as a prisoner, until Dorothy gets the information she wants about what happened to Jericho. This will lead the show into an episode so dark Ambrose admits when she first read the script first wondered, “How on Earth am I going to do this” before getting “angry and was like, ‘I don’t want to do this!'” and then realizing that the fact she was scared, just reading the story in her bed, was what was going to make it an extra special episode.

“I was nervous about women fighting in general and what that means in the world, but I have a teenager and the teenage will versus the material will is an interesting dynamic,” she says. “The crazier and darker the material is, it seems so challenging to do. But ultimately that’s what’s so fun as an actor: to play these extremes of human emotions. So for me, it’s like, ‘Bring it on, how crazy can we get?'” Plus, in general, she adds, “getting to scare people is fun.”

(That aforementioned fourth episode, entitled “2:00 A.M.,” is directed by Shyamalan.)

Working on “Servant,” Ambrose shares, has given her the “opportunity to learn this genre.” And one essential thing she has realized in her two seasons so far is that she is “always looking to make it funny.”

“Those are my favorite moments on the set, when we find things that are really funny or absurd, even if it’s not in a laugh-out-loud kind of way. There’s a lot of dark comedy that’s a nice tonal element that plays against the horror and devastation that the family is going through,” she explains.

“Everything is buried under layers of psyche that nobody can bear to look at, and that’s actually the fun of playing one of the characters. She’s constructed this mask and this façade, and it’s like a puppet or a glass doll that’s going to crack, which I think would be pretty interesting, if and when we get to see that happen.”

But, Ambrose admits she hasn’t yet given too much actual thought to what it would look like when the truth of Jericho’s death crashes down on Dorothy.

“I wonder that as much as maybe an audience member would, and probably I’ll say, ‘I wonder what that’s going to look like, how the fuck am I going to do that?’ as I read it,” she laughs. “You can’t hold all of the dynamics in your mind at once or it will get muddled. You just trust the writers and the other actors on the show; they’re such talented people. I am interested to see what will happen to not just Dorothy, but the whole family when they have to face their grieving.”

“Servant” streams new episodes Fridays on Apple TV Plus.