Kata and her fleet of Berserkers head for Berk, intent on eliminating the Berkians and Outcasts for their part in Dagur's defeat. While she pretends she's interested in renewing peace with Berk, part of her fleet and her dragon rider head to Outcast to rescue Dagur, a Valkyrie named Sigrún having revealed he still lived. Under the flag of truce, Kata entered Berk's harbor and gained the trust of Stoick and Hiccup, using the fact that she and Hiccup had been friends as children to assuage their fears.
Back on Berserk, Ingrid, the captured pirate, tells her captors a little bit about her queen. While there are many rumors about the pirate queen, the most common was that she died and returned with new power – like Lief. She, her real name unknown, was quite… efficient. She killed the leaders of the various factions of pirates and united them all under her rule. Shortly after that, she became the guardian of a pair of Nightfury brothers. The brothers are reported to be her shadows, obeying their queen's every call. They are quite bloodthirsty, having developed a taste for human flesh instead of fish and they even killed their sister, tearing her wings off.
The half of the Berserker fleet reaches Outcast, and Merrik and Skye leave to break Dagur out. While scouting the island, he is startled to find a second pirate fleet (the first destroyed in Part 1) in the Outcast's bay, leading him to conclude there is an alliance between them. He rescues Dagur, but is ambushed on his way back to his ship by the pirate queen's Nightfuries. Merrik is pulled out of the saddle by one of the brothers, fatally wounded as its talons pierce his chest.
When the scene cuts back in, the pirate queen is kneeling over Merrik's body as his heart slows, irked that Dagur and Skye escaped. She steps back to allow the Nightfury brothers to eat Merrik, but they are interrupted when the Valkyrie Sigrún appears and uses her power over death to stabilize Merrik. She teleports him back to the Berserker's ship with her magic, figuring Kata will need his help if she wants to win – and if Sigrún wants to win the bets she made.
Sigrún labels the furious queen as a god-touched like Lief and is promptly attacked by the queen's Nightfuries. The very young Valkyrie defeats them, although she uses up her magic during the fight. Frustrated by the "demi-human" affair Loki started she and the queen begin to fight directly. Merrik rematerializes on the deck of the Berserker's ship, startling everyone except Jodi, who was used to immortal interference, and she issues orders to have Merrik and Dagur moved below deck so she can tend to them. The Berserkers at Outcast sail Berk to join Kata in her attack, while on Asgard, Loki hums a song about how "the crown will be mine."
On Asgard, Váli and Nari Lokison walk across Asgard, heading to Niflheim per Odin's orders – they find the name of the Valkyrie who told the mortals Dagur still lived and he will release Loki from the dungeon. Their trek is interrupted when Thor and his favored sons, Magni and Modi, walk by, and Nari turns he and his brother invisible to avoid a confrontation. The pairs of brothers hate each other, partially because of an incident some years ago involving Váli shapeshifting into a wolf during a fight with Magni. Thor, thinking Váli was a real wolf, had attacked him with Mjölnir. Things had gone downhill from there. During the brothers' walk, there are hints of civil unrest on the supposedly peaceful Asgard.
The Berserkers from Outcast arrive at Berk and Kata begins her attack. She taunts Stoick for being gullible enough to believe she forgave him for what he did to her brother as Merrik clashes once more with Berk's riders overhead. During a brief skirmish with Stoick, Kata scratches his hand with a poisoned knife. Lief waits on the cliff's edge while Merrik lures Berk's dragons to him. He's the key to her attack. Using the abilities Loki gave him, he will telepathically force the dragons to submit to him, a tactic also seen in Bewilderbeasts.
He forces the dragons to land against their will and orders the riders to dismount. His compulsion forces them to carry out these actions without hesitation, leaving Merrik free to provide air support for the Berserkers. Lief uses the magic to halt two crossbow bolts shot at him. He idly complains to the riders that killing is boring for him now that he has power, but the terror in their eyes as they realize they are powerless makes it worthwhile. The riders are troubled by this side of his personality and Lief levitates one of the crossbow bolts, intending to kill Toothless, as Kata's orders were only to take Hiccup alive. To his shock, Hiccup jumps in front of the bolt and takes the hit for Toothless, making him crumple to the ground. Merrik, having returned, scolds him briefly for hurting Hiccup before kidnapping the Berkian and taking him back to the fleet. An unconscious Toothless is left on the cliff.
Lief levitates multiple pieces of shrapnel from a destroyed hut, intending to hurtle them at the riders and their dragons and kill them with one blow. He stops just before he does so, saying, "oh you brat," before collapsing. The second crossbow bolt has skewered him through the heart, killing him and freeing the enthralled Berkians. While Astrid is left puzzled by who fired the shot at Lief, she orders the riders into the air to begin a counterattack that was not supposed to happen. On Asgard, Odin, having remotely moved the crossbow bolt to kill Lief, observes a now quiet Loki. In his eyes, Loki had been allowed too much free rein. The death of his human champion was meant to remind him of his place.
Kata, watching the battle from a rooftop, is stunned to see Berk's riders and wonders what happened to Lief. Astrid has Stormfly launch a volley of spineshots, one of which impales Kata's arm to the roof as she attempts to dodge. She vows to return the favor as she returns to the ground, struggling with the poison. A pair of Berserkers lead her to where Stoick is and Kata assures him Hiccup is in her custody and she will kill him if he doesn't surrender. Knowing Kata will kill them all anyway and that Hiccup is likely already dead, Stoick refuses, but collapses seconds later as the poison she inflicted him with earlier takes effect.
Kata smugly states she learned from Dagur to always have a backup plan and tells Gobber to surrender or she will let the poison kill Stoick. He hesitates and she draws the poisoned knife, nearly dropping it as her hand is numb because of the spine's poison. Loki intervenes and touches her injured arm, purifying the poison. Realizing her god is with her, she states she'll fight with the knife and see how many Berkians she can scratch – a scratch is all she needs.
Overhead, Astrid sees the Berkians surrender and the Berserkers begin to provide ground support to Merrik – who is systematically downing the dragons, one by one. She is forced to call a retreat, knowing that if they are captured there will be no one to fight back. Willem finds Lief's body on the cliff and believes a cowardly Berkian has shot his nine-year-old brother in the back, prompting him to go berserk until Kata snaps him out and learns to her horror that Leif has been killed. Arin collapses by his brother's side, begging Lief to wake up, saying "we've won."
Later that day, the prisoners are being confined in the Great Hall and Kata is speaking with Merrik. She gives him permission to start training his own squad of dragon riders when they return home and mentions Hiccup and Toothless are imprisoned on Nemesis, writing all the time. When Vorg asks why she rescinded her earlier order of no survivors and suddenly had them take prisoners, Kata reveals she's writing a letter to the Lava Louts. Vorg is stunned as they are a slaver tribe, and Kata states she's going to sell the Berkians to them. The Berserkers will earn a tidy profit, and the Berkians will slowly be worked to death in the Lava Lout's mines, a far more fitting punishment then quickly executing them. Vorg fears the Lava Louts might try to enslave the Berserkers as well, but doesn't countermand her.
Astrid and the other Riders make it to the Cove, their fall back spot as they can't go to the arena. Their dragons are injured, but everyone is alive. She intends to send a message to Outcast, as Alvin is the only ally who might help them.
Now on Niflheim, Váli and Nari chat with their older sister Hela. She is reluctant to help them once she learns she will have to give up one of her Valkyries to free Loki. The Valkyries began as Odin's warriors, but many have recently begun giving Hela their oaths of loyalty. They claim Hela is the Goddess of the Underworld and they serve the dead – Odin is of the living and all living eventually die and become Hela's subjects. Odin has lost control of 2/3 of his Valkyries and the Einherjar, the deceased warriors of Valhalla to her, giving her the most powerful army in the realms. It is supposed to be Odin's army and since Hela is a daughter of Loki, Odin does not trust her. Friction between them has been steadily growing.
Brynhildr, leader of the Valkyries and the first to defect to Hela, interrupts them and cites that Sigrún, a Valkyrie of Hela's faction, has gone missing. Hela isn't worried since nothing much can threaten a Valkyrie, even one as young as her. She admits to the brothers Sigrún is likely the Valkyrie who revealed Dagur's survival. Brynhildr also tells her a soul is refusing to let the Valkyries take it away.
Lief reawakens on Earth, and remembers he died again. Blaming Odin, he tells Kata and his brothers the Allfather manipulated the crossbow bolt and calls him a brat. Lief effortlessly levitates one of Merrik's arrows to prove that Odin could have remotely killed him. Kata remembers that he strained to lift objects before his second death. She notices his eyes, which were once brown with green flecks, are now primarily green from Loki's magic. He abruptly threatens a nearby Valkyrie of Odin's to leave. The Valkyrie compares his aura to "malice oozing like a miasma." Both Kata and the Valkyrie are stunned she can see the immortal, as a mortal like her should not be able to. Fearing that Loki's tampering is beginning to blur the line between mortal and immortal, and fearing what Lief is turning into, she goes to report to Odin.
A pair of Valkyries on Midgard search for Sigrún, who is still missing. They comment that they can feel Lief's aura despite the great distance, indicating its strength, and wonder if what Loki did to Lief was a gift or a curse. Deciding it isn't their problem, they resume searching for their sister though they doubt she's here as they can't conceive how a mortal could be a threat to immortals like them.
Sigrún's is revealed to be unconscious in the hold of the pirate queen's ship, having been defeated and captured by the demi-human. The queen charges her lightning-affinity power to her knife and cuts Sigrún, proving she can bleed. She licks the immortal's blood off her knife, relishing in the rush of power as her body assimilates the strength of the Valkyrie. The queen has raised a barrier around her ship, preventing the other Valkyries from sensing Sigrún's presence. She knows of the tension between Hela and Odin and believes Hela will blame him for Sigrún's disappearance.
Alvin interrupts her musing, showing her a letter from Astrid asking for help. The queen initially decides to work with Alvin to attack Berk as it will give her ample chance to kill the other god-touched, Lief, but the immortal that enhanced her instead orders her to return to her island. She agrees, playfully warning Alvin that Kata, who is avenging her brother, would soon come for him. Alvin comments that it sounds like the queen knows the Berserker siblings, but the queen denies it and says, "know thy enemy." Her Nightfury brothers encourage Alvin to leave her ship.
The queen returns to her musing, stating this development will allow her to move her prisoner to a more secure cell at her island. She does not want any immortal, even the one who resurrected her, to learn she has a Valkyrie. If they knew, a civil war among the heavens might be averted.
Three days later, Merrik prepares to leave to deliver Kata's letter to the Lava Louts. He mourns Kata didn't let him shoot down the Terrible Terror Astrid was using to deliver her plea for reinforcements, but Kata is betting she's asking Outcast. This way, the Outcasts will come to her and she won't need to dig them out of their fort on Outcast Island to slaughter them. Merrik leaves with Kata's correspondence and Jodi runs up to her, announcing Dagur had regained consciousness and she no longer fears he will die.
Odin, having been told Lief won't stay dead, heads to the dungeon to get answers from Loki. On his way there, Fenrir, Loki's wolf-shaped son, stops and smoothly greets him. While Loki was malicious, playful, and helpful by turns, Fenrir was neither playful nor helpful. He takes great pleasure in using his silken voice to sow discord, more than Loki. Odin tells Fenrir to step aside and mistrustfully walks past him. He fears that Fenrir's audacity was becoming more prominent and that something would have to be done about him.
He reaches Loki's cell and demands to know what Loki did. Loki instead asks if Odin truly felt so threatened by a mortal child he would try to kill him. When he realizes Odin hasn't figured out what's happening he decides not to "spoil the surprise." Instead, he tells Odin to find who enhanced the second god-touched human. Odin had believed Loki was behind both demi-humans, but now rescinds that opinion, upset as it means a second god is disobeying him. His patience wearing thin, he thinks it is wrong for the mortal realm to affect the gods.
Next: PART 3: TREACHERY