For the second time this season, The Sinner begins with Detective Harry Ambrose behind the yellow police tape, studying a corpse. This time it’s Percys ex, Brandon, whom he and Meg found with a bullet hole in his head last week. Taking a closer look at the body, Ambrose discovers a pack of nicotine gum, much like the one he’d found near Percy’s favorite spot by the docks.
Over coffee with Meg Muldoon, he delivers his findings. Meg shares that Brandon had taken the sudden break-up with Percy pretty hard. I know he still had feelings for her. Back at the station, the big guns from Portland PD are questioning Mike Lam about his ongoing rivalry with the Muldoons and Brandon. But Ambrose angrily interrupts, saying the homicide was premeditated and clearly not the fallout of the ongoing fight between the fishing families. He insists they’ve got the wrong guy and they’re wasting their time. But the typically super lowkey Lou Raskin doesn’t appreciate the outburst You disrespected me and boots Ambrose off the case.
We next meet two new characters: Brandon’s mom and his widow. Megs consoling the former, while Harry pulls the latter aside for questioning. She immediately hits Harry with, They arrest that Chinese guy yet. The grieving mother is convinced her son was a good, honest man, who couldn’t have brought such a fate on himself, but his foul mouthed wife has a different take on her murdered spouse. Just because he’s dead doesn’t mean he wasn’t screwing half of Hanover. Things escalate even further when Meg asks the mom about Brandon and Percy’s meeting the night she stepped off the bluff to her death. She reads it as an accusation though, and swiftly shows Meg the door.
The arguing and accusations are also in full swing at the Muldoon household. Colin wants to buy out deceased Brandon’s fishing permit, but Sean thinks it’s a dying business they shouldn’t sink more money into. Meg doesn’t want to talk business at all, but rather pursue the connection between Percy and Brandon’s deaths. She and Ambrose believe Brandon was the hooded figure Percy knelt before in the security footage from the night of her suicide. Colin’s convinced they’re both paranoid, and that Percy killed herself and the Lams offed Brandon.
Meg eye-balls Percy’s empty place at the dinner table, kicking off a flashback of the family surprise, surprise engaged in a verbal battle over the business. Times are tough for the local fishing family, but Percy sees it as karma for the Muldoons Irish ancestors pillaging from the Native Americans who were there first, Living in balance with nature. Needless to say grandma’s not a fan of this hot take.
Following a tip from Brandon’s bitter widow, Ambrose tracks down one of his former employees. An ex-paramedic from Honduras, the man reluctantly recounts a strange encounter with his former boss. Brandon frantically called him one evening to tend to his female friend who’d had an accident. Sitting in Brandons truck, the womans frightened, and her foot is bleeding. With a wad of money in hand, Brandon tells the man, Fix her up and forget all about this. Before the woman’s fully bandaged however Percy shows up prompting Brandon to cut things short and speed off. If all that wasnt suspicious enough the man tells Harry the injury wasn’t the result of a fall as Brandon suggested. The woman had rusted ring nail a material used to build boats as well as wooden splinters in her foot.
Harry asks if the woman’s name was Valerie to which the man replies, She was too scared to say.
Back at the station, still-in-custody Mike Lam gets a visit from his wife. They apparently have a juicy secret she feels her husband should share with the police. She believes this truth will exonerate him, but he thinks it will make him look more suspicious. Megs also downtown requesting Percys case be re opened. CJ shows up, too. He s got something to share about Brandon, but the cop on duty is uncooperative. Outside, he reluctantly confides in Meg instead. Suspecting Brandon was up to something illegal, hed been following him. One night, he trailed him to a boatyard where two men promptly beat the crap out of Brandon.
Ambrose meets with Meg, who relays CJs tale. He tells her about Percy stumbling upon Brandons makeshift medical care center. She arranges access for him to the yard where Brandon got the beat down. When Harry arrives, he immediately finds boards with dangerously protruding ring nails. He also discovers a boat named Valerie. Meanwhile, Meg meets with a family friend and the boatyards owner Don, and asks about Brandon’s mysterious meetings on his property.
Aboard the good ship Valerie, Harry encounters a foul smell, swarming flies, tiny bunk beds, and childrens clothing. Meanwhile, Meg continues to press Don for details on Brandons late-night boatyard activities. He strongly urges her to let this go and move on, which he follows with an ominous thats what I had to do. Upon finding a small makeshift internet video studio on the ship, Harry urgently gets Meg on the horn. But the connection is bad. Worse than that two men the same pair that pummeled Brandon show up with rifles.
Following a harrowing hide-and-seek-and-run sequence, Harry who’s only brought a knife to this gunfight gets the jump on one of the goons and stabs him. Ambrose is injured in the scuffle but makes it to the road, where Meg comes to his rescue. She brings him to her house, where Sean is lurking in a corner and clutching a cell phone. He calls Colin. She brought him here. What do we do. Back at the boatyard the men whod been hunting Harry set Valerie ablaze.