The first season of USA psychological crime thriller “The Sinner” took its story, structure and tone from Petra Hammesfahr’s novel. But the second season is its own, completely original mystery.

Without a pre-existing plot to follow, Derek Simonds created a new story about why someone would commit a seemingly unprovoked murder. This time the culprit is a 13-year-old boy Julian (played by Elisha Henig), and it’s clear from the start that he is guilty. The show follows the first season’s structure of unraveling the complicated reasons behind the crime, a similarity Simonds wanted to echo intentionally.

“We felt like we hit the right sweet spot between a character-driven drama and a hopefully elevated genre piece,” Simonds tells Variety.

One of his top priorities, he says, is focusing on the psychological aspects of the investigation by Detective Harry Ambrose (Bill Pullman), who is called back to his hometown to help an up-and-coming officer (Natalie Paul) because of his connection with her father, and his recent fame with the Cora (Jessica Biel) case from season one.

“Season 1 I had designed deliberately with this idea that the experience with Cora just cracks the door open for Ambrose to investigate his psyche more deeply,” Simonds says. “He’s had a lot of these buried experiences in his past that he’s only glancingly referred to in season 1. … And so season 2 one of the main things I pitched from the start was, ‘Let’s learn more about Ambrose.'”

The second season will see flashbacks into Ambrose’s childhood, which draws some thematic parallels to what is going on with Julian. While “trying to save a child in the present,” Simonds says, Ambrose “ends up over-identifying” with Julian.

But the second season of “The Sinner,” Simonds says, is more of an ensemble than the Biel-Pullman two-hander of year 1.

“The sins of the child are never his alone,” Simonds says. Therefore, the show will explore “trauma and how people deal with trauma, how family systems affect people’s behavior later in life, how we never really grow out of those experiences that we inherit from our parents” from more than just the title character’s point of view.

Expanding in this way provided new challenges for Simonds, but it also opened the story up creatively.

“The tricky thing with ‘The Sinner’ is you always have a character who’s hiding the truth or who knows the answer, you can only stretch that out for so long,” Simonds admits. “With Cora it was an amnesia story, so it was about unlocking those memories [but] with Julian, he’s a child who only knows a portion of the story. And that was something strategic we realized was really compelling and created more questions. … The way I described it when we were working in the writers’ room is that these different perspectives are creating a mosaic that finally come together as one narrative.”

In addition to Henig and Paul, Carrie Coon and Hannah Gross are also key cast additions in the second season. He goes so far as to call Gross’ character Marin “the Laura Palmer of the show.”

“It’s actually [Marin’s] narrative and what happened to her that all of the other character perspectives are revealing,” he says. “That’s the mosaic that is coming together.”

Having central female characters proved key to the narrative as well.

“The sexual politics between men and women — the way that women struggle for power and self-actualization in today’s culture — that really resonated with audiences and with us as storytellers [in season 1], and we wanted to explore that again,” Simons says.

“The Sinner” season 2 premieres Aug. 1 on USA.