[This article contains spoilers from the season two premiere of HBO's Big Little Lies.]


While the first season of Big Little Lies was built around finding out who was murdered at a fateful elementary school trivia night, the second season is structured around the group of women at the heart of the mystery keeping the true nature of the death quiet. The implications of that secret, however, will bubble more trauma to the surface.


The second season premiere began with Nicole Kidman's Celeste experiencing flashbacks of her abusive husband, Perry (Alexander Skarsgard — who is back to reprise his role in flashback scenes) — that turned out to be a nightmare that she was awoken from by Meryl Streep, playing her mother-in-law, Mary Louise.


"You said rape — something about a rape," a concerned but suspicious sounding Mary Louise said as Celeste roused her twin boys to get ready for the first day of school.


Meanwhile, the other mothers of the Monterey Five — Shailene Woodley's Jane, Reese Witherspoon's Madeline, Laura Dern's Renata and Zoe Kravitz's Bonnie — all headed back to the private school in tony Monterey, Calif., for the first day of second grade. In a montage set to classic rock, the women hugged as they were reunited following a long summer of secret-keeping and enduring sideeyes from other parents, while also exchanging words with the principal and new teacher in the process.


Later, at a new coffee shop, Madeline and Mary-Louise's first onscreen run-in sizzled with disdain: "I can't complain — actually, I can. My son is dead," the pot-stirring Mary Louise said after Madeline exchanged pleasantries with her BFF's MIL, adding, "You're very short. I don't mean it in a negative way. Maybe I do. I find little people to be untrustworthy."


The Monterey Five weren't all coping well, either: Madeline and her husband, Ed (Adam Scott) were fighting, Bonnie was literally running from her thoughts, and Celeste was discussing her nightmares with her therapist, who told her that perhaps she needed to move on: "You're still married, Celeste, and your husband is dead."


Renata and Jane seemed to be doing okay, with Renata getting photographed for a magazine's Women in Power list and Jane delighting in her new job educating kids at the aquarium and flirting with a new coworker.


Madeline later confronted Mary Louise about her rudeness and clashed with her older daughter, Abigail (Kathryn Newton) when she said she didn't want to go to college (and couldn't understand why her mother was mad about it, since she didn't go). "That's exactly why you're going. Exactly. Because you will have no life," Madeline responded.


Since Madeline is a person who constantly concerns herself with other people, and she noticed that Bonnie did not seem herself at school drop-off, she took it upon herself to visit her to find out what was wrong. (What was wrong was the fact that Bonnie pushed Perry down a flight of stairs, killing him, and instead of letting her tell the truth, the women decided to cover it up and say it was an accident and that he slipped, rather than self-defense.)


She was right to feel uneasy about the situation, because Merrin Dungey's Det. Quinlan is still suspicious of the women, replaying their interrogation tapes from the night of the "accident."


Finally, at Celeste's house, Mary Louise rushed in as Celeste woke from another nightmare screaming, "I'll fucking kill you."


"So, who are we planning to kill?" she asked — Mary Louise is suspicious, too.


Big Little Lies author Liane Moriarty, who wrote the story for the second season, said at the season two premiere that the Mary Louise and Celeste storyline will be a central focus of the coming episodes — as will Bonnie's storyline, which is a significant change from the original novel. (The first season used up all the source material from Moriarty's bestselling book.)


"Bonnie has a really important storyline to come out," she said, "But yes, I think [Mary Louise] is the main problem. I think others might disagree with me, I don’t know. Just being the outsider. But there are a couple new characters."


Said series creator and writer David E. Kelley, "I would say we go a little bit broader, but mostly we go deeper. There are more stories to tell when you look at the Monterey Five plus one. But the key at the beginning was not to expand the canvas so much, although we do, but to drill down deeper on what we’ve got, especially when dealing with the malignancy of the lie. And that’s going to live at a very low level and it’s going to take a little spelunking in order to get at with the various characters. The biggest challenge for me was keeping the entertainment and the fun part along with the dark side. And we’ve been blessed with a pretty gifted group of actors.


"The seven-episode second season of Big Little Lies airs Sundays at 9 p.m. on HBO.