It is the dawn of the fourteenth century in Wales, when Catholicism rules the land. King Edward II is the monarch.
Our hero, Wilkin Brattle, dreams of a gory battlefield: swords clashing, blood spewing. In the midst of it all, a naked woman walks holding a cross, a crucifix set against the countryside background. In the dream/flashback, Brattle is stabbed (non-fatally). In the dream, he sees a white-haired young girl, who reaches her hand to him and helps him to his feet. He pledges himself her servant and she tells him he has a destiny to claim. The figure tells him to lay down his sword (her voice wavering between that of a young girl and an older Slavic-accented woman) and he agrees.
On the battlefield, Wilkin observes his dead brethren and closes the eyes of one of them. A dragon comes to life off of the blood on his dead friend's body and attacks him, jolting him awake and out of his dream/memory.
Awakening back in his home, Wilkin caresses the wooden cross around his neck and feels over his battle scars. His very pregnant wife enters their house, asking him about his dream. He denies having any dream, and says he sees only her. Wilkin makes sexual advances that Petra denies and they discuss their child; Annora, the local healer/witch, told the wife that the child will be a boy.
Wilkin and his wife play around, jostling about outside.
A man, called Erik, and a woman have sex. He finishes and comments that it is probably "wasted seed" as usual, implying that the woman is barren, though she tries to insist that they'll conceive a child soon by the grace of God. He leaves the room and a servant named Isabel enters, greeting the woman as Baroness. The Baroness gazes out the window mournfully.
A white-haired woman with a heavy Slavic accent, the witch/healer Annora, tells her hooded companion that it is time. Wilkin and Petra walk near the field by Annora and her companion, where a young man named Ash walks about with his sheep named Miriam. Wilkin points out that Miriam is a sheep, and Ash seems confused.
The Baron, seated on a toilet, discusses recent attacks with his Chamberlain, Milus, by a band of hooded rebels. A French servant wipes Erik's behind for him.
Toran and Calo, two villagers, inform a group of men including Wilkin (walking along with Petra) that the baron's tax collectors are on their way, sooner than expected. Wilkin expresses hesitation, but is convinced to ride along. Ash begs to go with them, and Wilkin obliges, telling him that he can go but can't fight.
Petra tells Wilkin that Ventris is sly and brutal, and that it is only a matter of time before Wilkin feels Ventris' blade. Petra tries to convince him not to go, while Wilkin explains why it is necessary.
Annora greets the couple, asking after the baby. She advises Wilkin of a remedy he should take for his wound.
A man (a torturer) is told by another man to finish the job (torturing a strung-up man). He slaps his son over the son soaking a rag in dumb paste. The son runs out and the father gets back to work on his prisoner.
The Baroness leaves Isabel at the shore holding her clothes and wades out into the sea, going beneath the surface. Isabel panics when Lady Love is under for too long, but the Baroness reemerges, commenting that the chill of the water reminds her of who she is: a hopeful Welsh girl.
Milus advises Erik to go for steeper taxes and tariffs. A messenger comes by saying another baron, Baron Pryce, wants his audience to complain of the steep tariff. Erik comments that if Pryce wants access to the sea, he will pay for it.
The Baron approaches a priest going over a bible verse with children. He wants to join them, but Milus pulls him away. Erik tells the messenger (Milus' half-brother Randolph, who they call a half-wit) to tell Pryce he is raising the tariff again. The messenger expresses hesitation, but Milus and Erik tell him to just go do it.
Petra bids her father farewell as he and Brattle go off to ambush the tax collectors. Toran bids farewell to his wife Eva and their son, telling his son to look after his mother. Petra says goodbye to Wilkin, who promises her that he'll be back soon.
The group of tax collectors are ambushed and slaughtered by the masked peasants; they let one tax man go, telling him to tell the Baron. The slaughtering villagers, led by Wilkin, laugh and celebrate their successful slaughter.
Ash talks to a butterfly and emerges from his hiding spot only to be nearly run over by the one fleeing tax man, who sees his face.
As Wilkin surveys the slaughter, he has a flash back to five years earlier, when the slaughter on the battlefield happened. He overhears Milus and Erik on horseback, who discuss that Milus' plan to leave him (Brattle) to die by the hands of the Scots has apparently worked. They consider whether they should find him and bring him back. They decide against it because if they do, the villagers will immortalize him and see him as a hero, so they don't look for him, leaving him there to die.
Back in the present timeline, Wilkin closes the eyes of one of the dead taxmen, and mutters a request for forgiveness under his breath.
At Castle Pryce, another shire, the messenger from Ventrishire reports back to Baron Pryce. Gawain Maddox, "the travelling punisher" (the executioner from the earlier scene in the torture chamber), approaches the desk in the Castle and is paid his wage. He confronts the men over his wage being half what is expected. They mock him and tell him to leave if he doesn't like it. Maddox ("Maddy" to his wife) takes his family and tells them that they're off to Ventrishire.
The tax man reports back to the Baron, Milus, Randolph (Milus' brother/the messenger) and the Baroness that his men were attacked and killed, and that he noticed that the watcher (Ash) wore a beaver pelt. They figure out where the beavers have a dam and set off to ride there. The Baroness mentions fair process for the accused to her husband, who assures her he will show fairness. When Milus and the Baroness are alone, he confronts her over her apparent concern for the outlaws. The Baroness expresses compassion and points out that there is nothing more dangerous than a Welshman with nothing to lose.
The villagers, camping by the woods, rib Ash over his habit of bestiality with the sheep Miriam. They discuss the fact that little is known of Wilkin prior to his arrival in their shire, and that even Petra knows little of his life before. They comment that Wilkin only uses oak and never a sword.
Toran privately confronts Wilkin over his resistance to fight. Wilkin states that he only serves God and his family, not the crown.
The Baron and his men storm the village. One of the men pulls Petra out of her house, asking where Wilkin is. She asks what is his right and he violently throws her out of the house. The men repeat their question: where are the peasant men? Petra quickly comes up with the lie that they are out hunting. Erik tells her he knows she's lying and threatens to cut Toran's son's throat if she lies again.
Eva and Petra tell the truth under the threat. Milus expresses disbelief that a bunch of farmers were able to overtake the noblemen. Milus/Erik cut the boy's throat anyway and proceed to slaughter many (if not all) of the villagers. Petra runs. The tax collector expresses horror at the Baron's actions, and the Baron commands Milus to kill the tax man.
Petra escapes when she convinces one of the Baron's men to let her go. He tells her to run far and not come back to the shire.
The Baron and his men continue to slaughter everyone in the village and burn everything down. Randolph looks around in horror.
Petra is confronted by an unseen assailant who fatally stabs her in the stomach and uses the blood from her womb to draw a cross on her forehead.
Gawain Maddox the executioner berates and abuses his son and his wife Jessamy as they camp out en route to Ventrishire.
Wilkin spots the smoke billowing from the village and rushes off. He and the other men come upon the pile of bodies of the villagers that were slaughtered, with Petra and her fetus on top. Toran spots the dead tax collector and proclaims that this is proof that the Baron and his men did this.
Wilkin flips out, cursing "devil Christ," and goes to dig up his old buried swords. The other men try to follow him; he tries to convince them to stay behind to tend to the dead, but they insist on going with him to seek vengeance.
Maddox mutilates himself with a hot sword as his family sleeps.
Wilkin and the villagers come across Annora and her masked/hooded companion in the Miscanthus Fields. She encourages them to change their purpose and says that their cynic has ties to the way of victory.
The Baroness gives the Baron a massage and he offhandedly mentions to her that he killed the villagers rather than returned with proof of their guilt, jarring his wife. Milus interrupts, telling them that the farmers are headed to their gates, seeking vengeance. They depart to confront them away from the castle walls and out of sight.
Maddox encounters the Baron and his men en route to confront the farmers. The Baron requests that Maddox come with them and they direct the executioner's family to head north and wait at the Baron's castle for Maddox's return.
Wilkin and the farmers, accompanied by a huge cohort of other rebels, confront the Baron and his men. Wilkin reminds the Baron that he is the knight that the Baron and Milus decided to leave to his death at the hands of the Scots. The Baron expresses disbelief that he could be alive, but shrugs it off.
The two groups fight, with members of both sides being killed in the battle. Maddox the executioner is one of the casualties (stabbed in the throat).
At the end of the battle, both the Baron and Wilkin are alive and are watched by the other surviving men as they sword fight one on one. The Baron warns Wilkin that London will quash his little rebellion, while Wilkin replies that he has no rebellion; only a need to see the Baron die. The Baron manages to stab Wilkin; Toran then stabs the Baron through the head, finishing him off.
Annora treats Wilkin's wound. Gruffudd, one of the rebels who joined the farmers, talks with Toran about the successful slaughter of the Baron and his men. Toran thanks the other man for joining up with them. Gruffudd tells Toran to mention to Wilkin that he may come back to collect on the favor at some point.
Annora cuts off some of Wilkin's hair and carves a cross into his face before she is stopped by the farmers, who ask what devilry she is performing.
Milus, who is having (possibly non-consensual) sex with the French servant boy, is approached and told of the slaughter. Milus orders the messenger to gather the men.
Wilkin awakens and asks the others who carved the cross in his face. They tell him it was Annora, the healer. He orders her binds cut and asks why she cut and scarred him. Annora tells him that she did it because his only chance at survival is to be supposed dead and gestures to dead Maddox, who has a matching cut on his face. She tells Wilkin that Maddox's death gives him that chance.
Annora tells Wilkin that the angel who confronted him on the battlefield spoke the truth. Wilkin is shocked that she knew about the angel and Annora tells him she hears the same voices. She echoes what the angel said to him earlier in the episode, about his savior needing him to lie down his sword and live the life of a different man -- but this time, she gestures to dead Maddox.
Wilkin and Toran ride toward the castle to deliver the dead, Wilkin wearing executioner garb and Toran disguised with a hood. They discuss Annora's plan, and that they are delivering the dead to avoid the bounty on their heads and suspicion.
The Baroness sees her dead husband and the priest orders the Baron be taken to the sacrament room, so Lady Love can mourn in peace. She asks Wilkin his name; Wilkin says that his name is Maddox, a punisher by trade, and introduces Toran as Marshal, who is aiding him in the capture of the accused.
Randolph accuses Wilkin of lying, saying he and Toran are two of the thieves. Wilkin and Toran argue against the accusation, calling Randolph a liar. The Priest calls forward Maddox's family to positively identify him. Wilkin apologizes the Jessamy beneath his breath and she covers for him. Randolph accuses her of conspiring with him.
Milus sides against Randolph, calling him a liar and having him sent off to be executed (since he apparently either lied or deserted prior to the slaughter, both of which are crimes punishable by death). Milus apologizes to the Baroness for the shame his brother has brought to them, and mentions it is fitting that the man falsely accused (Wilkin/Maddox) be the one most skilled to take Randolph's head. Wilkin looks startled.
Wilkin sits in the chapel, where the Baroness finds him. She quizzes him about his scar, which he tells her was given to him by a healer. Milus spies on the two, as Lady Love tends to Wilkins' wound.
Milus interrupts them to speak privately with Lady Love. He tells her that the timing of "Maddox's" and "Marshal's" arrival is good, as they can aid with keeping the law. He offers to draft the letters to bind them.
Milus tells Wilkin that the execution of Randolph is on for tomorrow. Wilkin questions him over his familial tie to Randolph. Milus tells Wilkin that he and Marshal will remain in Ventrishire. Wilkin asks Milus why he is doing this. Milus says that Wilkin's skills will prove useful to him.
Naked Annora and her heavily disfigured/scarred (formerly hooded) companion are in a cave. They both get naked in order to (in Annora's words) "renew their faith." The blade used to kill Petra lies nearby them.
The next morning Randolph's execution begins. Wilkin says "help me" under his breath and then hallucinates/sees a vision of Petra and their child. He puts down his sword and walks toward them, looking at the baby. Petra says to him "Always" and is led away by the hand by the young blonde angel girl.
Wilkin snaps out of the hallucination, and is handed a napkin by the man who spared Petra's life in the woods but kept her cross. The men joke that he will need the napkin because Randolph was "full of shit." He spots Petra's cross at the man's neck. He immediately goes back to the chopping block and cuts off Randolph's head abruptly.