What makes someone a "sinner"? If season one of The Sinner taught us anything, it's that transgressing, or establishing the right and wrong of a story, isn't always black and white.
Swimming in that grey area is what drives season two – and makes it just as brilliantly addictive.
"'Sinner' is an ambiguous sort of label in many ways," actress Jessica Biel, 36, tells TV WEEK.
"All human beings have been sinners at some point and done things we are not proud of."
After starring as troubled young mother Cora Tannetti in the first season, Jessica is now moving behind the camera as a producer for season two.
"It's very different," she says of the shift in roles. "For a minute, it was a bit hard to swallow because I had such an incredible time during the first season and it felt like my baby."
By working behind the scenes this season, Jessica's influence has helped give the series a feeling of continuity.
Season two centres on a new crime, even more chilling than the last, because now the "sinner" at the heart of the story is a young boy.
The culprit being a child brings a new level of intrigue and the series becomes all the more addictive. And Julian, played by Elisha Henig, is captivating.
"We had a lot of very challenging elements to fill to cast this person," Jessica explains. "You have to find someone able to appear wise beyond their years. Elisha is really a rare and unique young person."
Bridging the gap between the unrelated crimes in both seasons is Detective Harry Ambrose (Bill Pullman).
The crime is committed in Harry's home town, so he returns following a request for assistance from the local police department.
"Harry is such a difficult guy that, instinctively and initially, you like – or at least you want to like – and trust him," Jessica says.
The complex and often enigmatic cop will have his own mysterious backstory explored as we move into the second season.
"He really is trying to uncover the truth of his own trauma – and probably the truth of other people's trauma as well," Jessica adds.
The Sinner season two premieres on Netflix on November 9.