The Sinner's season finale gets off to an appropriately scary start. Jamie has fully embraced his dark side. Sporting a black beanie and squatting over an army of scrambling ants, he hauntingly recites "...prickly pear...” A few feet away, the Dorchester police captain's blood seeps into the sand-trap.
Burns celebrates his deadly attempt to get Detective Ambrose's attention with a meal. While methodically munching his food at a diner, he glares at a young woman snapping selfies with an impressive stack of strawberry pancakes. Police cars race by the window, sirens blaring, as they head to the Twin Oaks golf course.
At the scene, Ambrose takes a moment with his recently murdered boss while a forensics team waits in the wings. Detective Soto's on the scene. Harry tells him to take the lead. “You're in charge now. That's what the captain wanted.” An envelope addressed to Ambrose is discovered on the body. There's a paper fortune teller inside with four names written on its flaps — Sonya, Eli, Harry's daughter, and the captain. The latter has an “X” through it.
Harry immediately gets on the horn with his daughter to ensure his family's safety. Meanwhile, Jamie turns his phone off while waiting outside Eli's soon-to-be-dismissed karate class. The Dorchester PD discover his last location was near Ambrose's family. Harry hits the road while putting in a warning call to Sonya. “He's targeting people he knows are important to me.”
When he arrives at his daughter's house, he tells the worried mom his suspect is baiting him. He promises to find Eli. Back at Sonya's, the artist's enjoying a cup of tea despite Harry's insistence she get the hell out of there. It's not long before Jamie lets himself in. “You know I'm here to kill you.” As he waxes philosophical as only he can, she tries to talk him down. He walks away — “You shouldn't have stayed here” — before pulling a knife from his jacket.
She warns him the police are on their way. He chases her around the kitchen table, then pins her to the floor, blade at the ready. The cavalry crashes through the door to find an out-of-breath Sonya on the floor. She's unharmed, but Burns is in the wind. Back at the station, Harry checks in on her and asks why she didn't heed his warning. Sonya says she couldn't resist. “It was like a test. I wanted to survive it.” She urges Harry not to face him alone and make the same mistake she did.
In the station's command center, officers and detectives scramble to determine where Burns is and what his next move might be. Ambrose insists his suspect isn't trying to escape but is planning something in Dorchester. “He's making a point. He wants to torture me, bring me to the edge, where he is.”
While Harry and his team mobilize, Jamie's sneaking past the patrol protecting his wife. Whatever he's got in store for Ambrose, it seems he wants to see Lela one last time. He goes to their closed, glass patio door. Lela spots him and approaches. Without words, they share a tender, tearful moment, placing their hands together, with only the glass between their palms.
As Soto holds a press conference at the station, Harry's phone rings. It's Eli's number. He picks up. Jamie's on the other end. “You're getting low on milk, Harry. You might want to pick some up," he teases, before instructing the detective to go home (without back-up) if he wants to see Eli again. Harry grabs his jacket, quietly leaves the police station, and heads home.
Outside the residence, Harry exits his car, carefully shuts its door, and draws his weapon. He skulks around the house's exterior in the moonlight. He sees Eli, staring out the window, looking terrified. Before he can signal to his grandson, Jamie gets the jump on him. Upon repeatedly whacking Harry with a fireplace poker, Burns is able to grab the detective's gun. He points the pistol at him, ordering him inside.
He directs Harry to put Eli in a chair facing the wall with headphones on his head. Ambrose sits on the stairs behind the boy. Burns gestures the gun toward an item. “I made that one just for you. For tonight. Pick it up.” Ambrose reluctantly takes the item in his hand. It's a paper fortune teller. Three of its four options ensure Eli's safety. “One says Eli dies,” explains Burns.
The pair argue back and forth, Jamie insisting he play the game, Harry refusing to. Burns continues to press, recounting how Ambrose betrayed him. “I'm on the f---ing edge because of you. I want you to play the game!” The detective won't comply. “I want you to look death right in the face,” Burns says, before turning the pistol on Eli. He threatens to pull the trigger if Ambrose doesn't play the game, then fires a shot above him. Harry calls his bluff. Jamie turns the gun on him, then points it at his own head. Harry tackles him, taking a slug to the shoulder in the process.
He tells his grandson to run and get help while he stumbles close behind him. He then heads for the woods, Burns — with pistol secured — gives chase. He fires a shot at Harry, who's taking a look at the hole in his shoulder. Jamie trades the gun for a very big stick and starts hitting Harry. Ambrose sneaks in a shot with a rock and takes the opportunity to run back to the house.
Of course, Harry's got a combination safe that holds his back-up snub-nose. He enters the combo just in time to grab the gun and point it at Jamie, who's pointing a pistol right back at him. Burns cuts the showdown short, putting his gun down, and unloading a clip full of Nick-inspired BS instead. “Until you bring what's unconscious into consciousness, it will control your life. And you will call it fate.”
He wants Harry to admit they're the same. “Nick was my fate and I am yours. You can't outrun this.” As he continues to badger, maybe hitting a little too close to home, Harry becomes increasingly annoyed. He shoots Jamie in the gut but immediately looks surprised as if he couldn't control himself. He calls Soto and requests an ambulance.
Jamie's scared, begging for help. His wound is gushing. Ambrose applies pressure with a towel. He apologizes to Jamie. Burns becomes more terrified when he loses feeling in his legs. A far cry from Nick — who seemed to welcome death while bleeding out on the hood of his car — Jamie reacts just as you'd expect a gunshot victim to react. He's crying, terrified, emotional. Harry tries to calm him down and calls Soto back to check on the ambulance.
Jamie asks if help will arrive on time. Ambrose doesn't answer him. As Burns coughs up blood, it becomes clear he's not going to make it. With absolute terror in his eyes, he pleads, “I don't wanna die. I don't wanna die.” Ambrose desperately attempts to comfort him, continually assuring him he's not alone. Jamie asks Harry to hold his hand. As the last bit of life drains from Burns, Harry caresses his head and tells him everything's going to be okay. It might not be the ending fans were hoping for with Jamie, but there's no denying his extended death scene packs one hell of an emotional punch.
Sitting in the ambulance that arrived too late, Harry stares at the blood caked into the crevices of his hand. As Burns' body is wheeled out, Soto arrives. He informs Harry that Eli is safe. Ambrose confesses he “made a mistake” and will have to report to FID. “I don't think you'll have to worry about that,” responds Soto.
The next day Harry — complete with cast, sling, and crutches — arrives at Sonya's. They drink and prepare dinner before diving into some real talk. Sonya shares that she saw Lela in town and she seems to be hanging in there. The conversation quickly turns to the bigger elephant in the room. “I keep thinking about him,” she says, before asking what he was like at the end. After a lengthy pause, a somber Harry responds, “Scared.” He then begins to sob.
With tears welling in her own eyes, Sonya goes to him. They gently hold heads, bring their faces together, and The Sinner's third season cuts to black one last time.