A child of Loki with the ability to shapeshift between human forms and a gender identity that shifts accordingly. Alex uses he/him or she/her pronouns depending on the day. Prickly, lethal with a garrote, and one of the most distinctive characters Riordan has written.

Hearthstone's deceased younger brother, killed by a brunnmigi at the family well as a small child.

Slimy fish-skin dwarf in a Boston subway pool; owner of the cursed gold and ring that Hearthstone takes as wergild.

A daughter of Athena and Percy's closest companion and eventual partner. Brilliant, driven, and deeply competitive, she has been training at Camp Half-Blood since she was seven. Her fatal flaw is hubris - she believes she can do anything. Her arc through the series is about learning that intelligence alone is not enough and that asking for help is not weakness.

Samirah al-Abbas's grandmother; raises her in Boston after her mother's death.

A dwarf and son of Freya with an extraordinary gift for fashion and craftsmanship. One of Magnus's two companions from his mortal life. His sense of style and his skill with materials are not separate things - he makes weapons and armour of genuine power.

Queen of the Aesir, Odin's wife; offers Magnus mead and wisdom in Asgard.

Draugr king of Provincetown burial mound; keeps the Skofnung Sword that can wake the wight-bound.

A berserker einherji from the Viking era who died during the invasion of East Anglia in 865 CE, taking twenty arrows protecting his thane. Enormous and wild-bearded, he wears patchwork animal pelts and fights with double-bladed axes. Despite his ferocious appearance, he has earned a doctorate in Germanic literature and learned to knit during his twelve centuries in Valhalla.

An elf and one of Magnus's two companions from his mortal life. Deaf, communicates in sign language. A rune magic practitioner of exceptional talent from a family that considered his deafness a source of shame.

Guardian of the Bifrost rainbow bridge; obsessed with selfies; helps move the quest from Midgard to Asgard.

Stone-hearted giant; father of X the einherji; referenced in connection with X's lineage.

Huldra (cow-tailed nature spirit) employed as a servant at the Alderman estate; loyal to Hearthstone.

A talking sword, the Sword of Summer (Sumarbrander), the blade of the god Frey - sharp-tongued, opinionated, and prone to acting on his own.

Samirah al-Abbas's grandfather; raises her in Boston after her mother's death.

Norse god of mischief and Sam al-Abbas's father. The primary antagonist of the Magnus Chase trilogy. Imprisoned by the gods for his role in Baldr's death, he manipulates events from captivity until he can pilot Naglfar into Ragnarok.

A son of Frey, Norse god of summer, who dies on his sixteenth birthday and wakes up in Valhalla. Annabeth Chase's cousin. His voice - wry, self-deprecating, and unexpectedly thoughtful - distinguishes him from every other Riordanverse narrator.

A fiery Irish einherji with frizzy red hair, green eyes, and a sharp tongue. She died trying to disarm a car bomb and fights with a serrated knife and a sword. Tough and prickly on the surface, she cares deeply about her hallmates, especially Halfborn Gunderson, with whom she has a combative but affectionate relationship.

Hearthstone's tyrannical father; demands ruinous wergild for his son Andiron's death; transformed by the cursed Andvari ring.

Magnus's uncle and the eldest of the three Chase siblings. A former Harvard history professor who was disgraced and fired, Randolph is obsessed with proving Norse exploration of North America. He lost his wife and daughters in a shipwreck while searching for Viking artefacts and lives alone in a large Back Bay brownstone filled with Norse relics.