Norse Mythology is a 2017 collection of short stories by British author Neil Gaiman. The stories are retellings of tales from ancient Norse mythology, presented mostly in retrospect by an unnamed narrator. Through frequent addresses to the audience, the narration evokes the oral tradition of storytelling.

In the beginning, there was nothing but darkness and fire until the creation of the nine worlds. Odin and his brothers create other beings; Odin, the all-father breathes life into them. The nine worlds are joined by the world tree, Yggdrasil. Among these worlds are Asgard, the world of the gods, Midgard, the world of the mortals, and Muspell, the world of flame, and Jotunheim, the world of the giants. In Jotunheim, Odin sacrifices his eye to drink from Mimir’s well of knowledge.

Loki, the trickster god, cuts off Thor's—the mightiest of the gods—wife's hair. To assuage Thor’s anger, Loki tricks dwarves into fashioning treasures for the gods. Among these treasures are Odin’s spear, Gungnir, and Thor’s hammer, Mjolnir—the mightiest weapon in Asgard.

Loki’s sneaks off three times and each time has a child with the giantess, Angrboda. His daughter Hel becomes the ruler of the underworld. His child Jormungundr becomes the Midgard serpent, which will grow to encircle the world and kill Thor during Ragnarok. His son Fenrir, a giant wolf, is tricked into bondage by Odin, because Odin has had visions of Fenrir during the end times. Fenrir vows vengeance against the Aesir.

Kvasir, the wisest of the gods, is born of the commingling of the spit of the Aesir and the Vanir. He is tricked by two elves, killed, and turned into mead. This mead is the origin of all poetry in the world. Odin steals the mead from the giant, Suttung.

Thor, Loki, and Thialfi—Thor’s mortal bondservant who can run faster than anyone—journey to the land of the giants. The biggest giant they encounter, Skrymir, suggests they travel to meet Utgardaloki, a giant king. Utgardaloki challenges the three travelers to contests, which turn out to be illusions. Loki can eat almost as fast as a wildfire consumes matter. Thialfi can run almost as fast as a thought travels. Thor can drain the ocean and can nearly hold his own against old age.

Frey has everything he could want, but something feels like it's missing. He sneaks his way to Odin’s stronghold and sits in his throne. From there, he sees and falls for the beautiful Gerd. He sends his servant to fetch her, and the two are soon married. He gives his servant his magical sword as payment; this leads to his death at Ragnarok.

In order to obtain a cauldron large enough to brew mead for the gods, Thor visits the sea giant, Hymir, stepfather of the war god, Tyr. Thor and Hymir go fishing. While Hymir catches whales, Thor catches and nearly hauls in the Midgard serpent.

Thor and Frigg’s son, Balder, is the most beloved of the gods. In order to avoid a prophesy that seems to indicate he will die, Frigg makes everything—except mistletoe—swear an oath that it will not harm him. Loki gives Balder’s blind brother, Hod, a mistletoe dart to throw. This slays Balder.

The gods capture Loki and his sons. They make his son Vali kill his other son, Narfi. They use Narfi’s entrails to bind Loki to a stone in a cave. The wind a serpent in the stalactites above him; from then until Ragnarok, the serpent drips poison into Loki’s face. His wife, Sigyn, collects the poison as it drips to spare her husband the agony.

Ragnarok will be signaled by a winter that never ends. Fenrir, grown impossible huge and powerful, will escape bondage—as will his father, Loki. The Midgard serpent will flood the world and poison the ocean. Loki will go to Hel and raise an army of the ignoble dead. Heimdall, the watchman god, will sound the alarm. Odin will raise an army of the warriors of Valhalla and lead the gods into battle.

Frey will fall to Surtr of the fire world. Thor will fall, poisoned after slaying Jormungundr. Odin will be consumed by Fenrir, and avenged by his son, Vidar. Loki and Heimdall will fall in battle together. All will be reduced to ash, except for Yggdrasil and those taking refuge in its branches. The few surviving Aesir—along with Balder, back from the dead—will make up the pantheon of Idavoll; the world will begin again.