Kaaval

In Kattappana, an amputee named Antony sits drafting a letter to his estranged friend Thamban while his daughter Rachel stitches garments. Preparing for her upcoming wedding, Rachel asks her father to leave Thamban out of their lives, stating, "Don't invite him to my wedding. We're suffering now because of whatever you and he did together in the past. You lost your leg." Shortly after, moneylender George of Kuzhiyil Finance arrives to demand thirteen and a half lakh rupees borrowed across decades. Threatening to claim Rachel in installments if the debt is not cleared, George warns, latestnetflix.com argues, "If you don't pay off your debt before marrying her off… I'll take her with me!"

Antony's son Alex is stopped and taunted on his way home by local men who invoke his father's past. The following day at church, masked men leap from a vehicle and beat Alex on the ground in front of the congregation. Antony tries to shield his son with his body, but the attackers overpower him and flee.

Antony limps into the Aanakkuzhi police station seeking protection, accompanied by writer Aravindan. The Sub-Inspector refuses to register a case, recounting how Antony and Thamban previously antagonized former SI Muralidharan. The officer tells Antony, "Even if they beat you and your children to death on the street like dogs, no one wearing a khaki from this station will come to help you." Antony replies, "You might not have any limits, sir. But my patience… does have a limit!" Antony returns home and tells Alex they must travel far away to seek help.

Antony sets out on the journey alone but dies under suspicious circumstances before reaching his destination. Following the burial, Alex travels to Kollengode in Palakkad to locate Thamban. Alex finds Thamban's residence and introduces himself as Antony's son. Thamban asks after Antony and Rachel, and Alex breaks the news of his father's death.

Back in Aanakkuzhi, George enters Antony's house and demands that Rachel marry him to settle the loan, suggesting Alex will otherwise have to pimp her. Alex fights George off, but Rachel locks herself inside a room and attempts to hang herself. Alex forces the door open in time to cut the rope and save her life. When Alex urges Thamban to return to Kattappana, Thamban initially demurs: "I can't go back to that place. I'm sure you've heard several stories as well. I'm not who I used to be." Alex leaves, insisting that Rachel will never abandon their family home.

Years earlier, Thamban and Antony operated a timber mill in Aanakkuzhi while acting as local arbiters who confronted loan sharks and protected estate laborers. When tea estate owner Vaalara Maani raped a worker and left her pregnant, Thamban and Antony forced Maani to provide funds for her welfare. Maani filed a complaint with SI Muralidharan, prompting the police to search Antony's house and harass his wife Mary.

Thamban and Antony subsequently cornered Head Constable Varghese on a road, warning him, "With this, your game is over, Varghese! This is your full stop!" Varghese jumped to his death. In retaliation, Muralidharan arranged for an ambush that resulted in Antony's leg being hacked off. At the hospital, Mary banished Thamban from their lives, stating, "You shouldn't see each other anymore. If you did, nobody would be left alive. Go from here." Thamban retaliated by executing Maani before departing from Aanakkuzhi.

In the present, thugs ambush Alex on the road. Thamban intercepts the attackers, beats them, and warns, "Don't dare come this way even if the God of Death is chasing you! I'm here to guard. Don't turn me into an executioner." Thamban brings Alex home and informs Rachel that he has returned to protect them, taking up residence in their house.

Thamban accompanies Alex to Kuzhiyil Finance. George claims the outstanding debt has reached eighteen lakh rupees and brandishes his mobile phone, declaring, "Your sister's showering video is on this phone." Thamban strikes George, confiscates the phone along with the pledged deed, and tells him, "I'd like to play rummy. Not here, but at the church cemetery… upon the tomb where you'll be buried! Sitting on that slab!"

The local SI stops Thamban on the street, beats him, and locks him in a cell at George's request. Released late that night, Thamban is dismissed by the officer as harmless ash. Thamban replies, "Don't try to scrape thinking that it's just ash. If there's even a tiny spark… it will burn you."

Arrangements move forward for Rachel's marriage to a teacher named James, scheduled for February. Simultaneously, Thamban investigates the day Antony died. A driver recounts that Antony had boarded a jeep driven by Thomas, a man who perished alongside Antony in an alleged road accident. Thamban deduces that Antony never made it beyond the local police jurisdiction on the day of his death, noting, "Antony had set off to see me that day. But he couldn't go beyond this locality."

While walking home from the market, Rachel is run down and critically injured by an oncoming vehicle. At the hospital, the SI attempts to question Rachel while she is sedated. Thamban restrains the officer, forces him to disclose the location of the assailants, and tracks them to an old club, where he incapacitates the men involved.

The police search for Thamban, leading the SI to the church late at night. Parish priest Father David stops the officers from entering the premises without a warrant, prompting the police to wait outside. Inside, Thamban confronts Father David regarding Thomas's vehicle, pointing out that the jeep was laden with banana shoots when Antony entered it, yet was found empty at the crash site.

Father David admits to orchestrating the attacks on Antony's family. Revealing his parentage, he says, "Do you remember the old head constable, Varghese? He was my father. My father!" David explains that he joined the priesthood solely as a cover for vengeance, declaring, "I reluctantly wore this cassock and biretta only as a hideout to reach here like this." He recounts how he murdered Antony inside the church grounds before staging the accident scene with Thomas.

David pledges to ruin Antony's surviving children, but Thamban responds, "I will be there for them… as their guard." Thamban executes David inside the church. When an officer steps inside upon hearing the disturbance, the death is reported to the SI as a suicide, leaving Thamban free to continue standing guard over Rachel and Alex.