Sky in the Deep (sky and Sea, #1)

Two rival clans have fought each other every five years for generations in an ancient blood feud. The Aska worship Sigr, the god of the fjord, while the Riki worship Thora, the god of the mountain. Seventeen-year-old Eelyn is an Aska warrior who fights with a sword in her right hand and an axe in her left, a style taught to her by her older brother Iri, who she believes died five years ago when he fell into a trench during battle. She fights alongside her father, Aghi, and her fighting mate, Mýra.

During the battle at Aurvanger, a Riki warrior named Fiske nearly kills Eelyn, but a fair-haired man tackles Fiske and stops the blow. Eelyn recognizes the man as Iri, older now but unmistakable. Before she can react, Iri tells her to run and disappears into the fog with Fiske. Eelyn tells her father, but Aghi believes Sigr sent Iri's spirit from Sólbjørg, the Aska afterlife, to protect her. Eelyn is shaken because Iri appeared physically real.

That night, the Riki raid again. Eelyn spots Iri and chases him into the forest. Fiske intercepts her, but a third Riki discovers them. Iri gives Fiske a silent nod, and Fiske chokes Eelyn unconscious. She wakes bound in a cart, being transported toward the Riki mountain. She attempts escape on a stolen horse, but Fiske shoots an arrow through her shoulder.

In Fela, the Riki mountain village, Fiske removes the arrow with Iri's help. Fiske warns Eelyn that Iri is his brother now and threatens to kill her if she endangers him. Iri visits Eelyn and explains that the Aska left him for dead, but the Riki saved his life. He urges her to accept becoming a dýr, a bonded servant, to survive the winter and return home after the spring thaw. Eelyn is horrified because a dýr forfeits honor and possibly entry into Sólbjørg. Before Iri can arrange anything, Riki men drag Eelyn out before dawn and a blacksmith locks a hot iron collar around her neck, branding her as a dýr.

Fiske intervenes when a stranger gropes Eelyn during the sale, paying for her himself. He brings her to his household: Inge, his widowed mother and the village healer; Halvard, his young brother; and Iri, who lives with them as family. Inge assigns Eelyn chores and warns her not to cause trouble. Eelyn burns the wooden idol of Iri she has carried since his supposed death, symbolically releasing the brother she knew.

Life in Fela forces Eelyn into uncomfortable proximity with the Riki. Halvard befriends her despite warnings to stay away. At the Adalgildi ceremony honoring Riki warriors, the Tala, the clan's spiritual leader, blesses the returning fighters, including Iri. Watching Iri receive the Riki blessing cuts Eelyn deeply. A Riki man named Thorpe harasses Eelyn afterward; she holds his own knife to his throat before Fiske pulls her away. In the forest, Fiske tells her that her pride and anger will be her undoing.

Over weeks, Eelyn learns the full story of Iri's survival. Inge tells her that Iri and Fiske fell into the trench together and Fiske begged his father to save Iri. Inge healed Iri over many months, and he became part of their family. Fiske's father offered Iri the choice to return to the Aska, but Iri chose to stay, having fallen in love with Runa, a young apprentice healer. Inge also reveals she has deduced Eelyn is Iri's sister and promises not to tell anyone. She explains sál fjotra, a soul bond formed through shared suffering, which connects Iri and Fiske. Eelyn recognizes she shares a similar bond with Mýra.

When Eelyn helps Fiske check fishing nets at the river, an enormous brown bear approaches and stares into her eyes. The Tala later identifies the encounter as an omen from Thora. Thorpe attacks Eelyn again, tying her naked to a tree in the forest to freeze to death. The Tala witnesses the attack but walks away without helping. Fiske finds Eelyn and carries her home, then confronts Thorpe.

Everything changes when the Herja, a mysterious raiding clan, attack Fela at night. Fiske returns Eelyn's weapons, and she kills two Herja who enter the house, protecting Halvard. When a Herja captures Halvard, Eelyn and Fiske pursue together and rescue the boy. Eelyn also frees the Tala by throwing her a knife. The raid kills 54 Riki. A captured Herja carries Aska weapons, and Eelyn interrogates the prisoner, learning the Herja have raided six Aska villages and four Riki villages. The threat dwarfs the ancient rivalry. Fiske offers to guide Eelyn down the mountain to her home village of Hylli.

Eelyn and Fiske travel together, their bond deepening along the way. When they crest the bluff overlooking Hylli, Eelyn finds her village burned and destroyed. She breaks down in grief, but Fiske observes that the Aska bodies were properly burned and the house cleaned out, meaning survivors remained. That night, beside the fire in her ruined home, they share their first kiss.

Mýra discovers them and nearly kills Fiske with an arrow before Eelyn intervenes. Mýra reveals that Aghi is alive and survivors have gathered at Virki, a hidden Aska refuge where about 290 fighters await. Eelyn reunites with her father, who weeps with relief but is shaken by the burn scars on her neck. Fiske presents the Riki's proposal to Espen, the Aska clan leader: The Riki want the Aska to join them against the Herja, with a truce afterward.

On the journey back toward Fela, Eelyn tells Aghi that Iri is alive. Aghi is devastated by guilt but abandons a secret plan he and Espen had devised to betray Fiske and attack the weakened Riki. Mýra, consumed by grief, attempts to kill Fiske in his sleep. Eelyn fights her to protect him, then comforts Mýra when she breaks down.

In Fela, Aghi embraces Iri and weeps openly, his love for his son overwhelming any impulse toward punishment. The Riki leaders propose a joint fight against the Herja and a permanent truce. Eelyn and the Tala seal the alliance with a blood oath, cutting their palms and clasping hands. Fiske has the blacksmith remove Eelyn's dýr collar, telling her she will not go home as a dýr. Eelyn chooses to stay with Fiske and the Riki forces rather than return with her father. Fiske tells her he wants to live with her in Hylli after the battle. On the eve of battle, Eelyn prays to both Sigr and Thora for the first time, asking each god to protect her loved ones on both sides. Fiske slips a taufr, a Riki protective talisman, into her armor.

The combined forces execute a joint plan. The Aska raid the Herja camp at night, then retreat toward the fjord, leaping off sea cliffs into the water to draw the enemy after them. The Riki, positioned in Hylli, engage the Herja on the beach and in the village. Eelyn and Mýra fight side by side. A Herja nearly drowns Eelyn, but Fiske kills the attacker and pulls her from the water. The combined forces defeat the Herja.

In the aftermath, Iri and Runa marry in Fela in a ceremony attended by both families. Eelyn and Fiske return to Hylli to rebuild, and Inge and Halvard eventually settle there as well. The fighting seasons between the Aska and Riki end permanently. Halvard grows up among Aska children, representing a generation that will not inherit the blood feud. Eelyn reflects that she is the same person but fundamentally changed: Her heart, once filled with hatred for the Riki, now belongs to them in many ways.