Although he had once been adopted into the circle of gods, as a blood-brother by oath of Odin himself (Lokasenna 9) Loki became a jotun again once he murdered Baldur and was chained in Niflhel by the gods for it. We see him as "Uthgarlocus" in Saxo's Danish History Book 8. His hair and beard are grown out like stalks of cornus and are as hard as horn. His next act will be to lead an army against the gods, on the northern and eastern front of the battle of Ragnarok. We are told that Heimdall and Loki fight one another to the death, and that Heimdall died when he was pierced with a head (thus a head can be called a sword). Loki's appearance in Saxo explains how. Once Heimdall severs Loki's head, which is poetic justice for having lost his head in a bet and keeping it, the severed head with its horny spikes, becomes a deadly weapon which kills Heimdall. The broken spikes are poisonous according to Saxo.

Saxo Book 8: In this ship they sailed away, and came to a sunless land, which knew not the stars, was void of daylight, and seemed to overshadow them with eternal night. Long they sailed under this strange sky; at last their timber fell short, and they lacked fuel; and, having no place to boil their meat in, they staved off their hunger with raw viands. …Then, when they were beginning to be in utter despair, a gleam of unexpected help relieved them, even as the string breaks most easily when it is stretched tightest. For suddenly the weary men saw the twinkle of a fire at no great distance, and conceived a hope of prolonging their lives. …When he got to the shore, his eyes fell on a cavern in a close defile, to which a narrow way led. Telling his companions to await him outside, he went in, and saw two men, swart and very huge, with horny noses, feeding their fire with any chance-given fuel. Moreover, the entrance was hideous, the door-posts were decayed, the walls grimy with mould, the roof filthy, and the floor swarming with snakes; all of which disgusted the eye as much as the mind….Then one of the giants greeted him, and said that he had begun a most difficult venture in his burning desire to visit a strange god, and his attempt to explore with curious search an untrodden region beyond the world….The giant was pleased with the shrewdness of Thorkill, and praised his sayings, telling him that he must first travel to a grassless land which was veiled in deep darkness; but he must first voyage for four days, rowing incessantly, before he could reach his goal. There he could visit Utgarda-Loki, who had chosen hideous and grisly caves for his filthy dwelling. …With his crew he entered a land where an aspect of unbroken night checked the vicissitude of light and darkness. He could hardly see before him, but beheld a rock of enormous size. Wishing to explore it, he told his companions, who were standing posted at the door, to strike a fire from flints as a timely safeguard against demons, and kindle it in the entrance…..Then he made others bear a light before him, and stooped his body through the narrow jaws of the cavern, where he beheld a number of iron seats among a swarm of gliding serpents. Next there met his eye a sluggish mass of water gently flowing over a sandy bottom. He crossed this, and approached a cavern which sloped somewhat more steeply. Again, after this, a foul and gloomy room was disclosed to the visitors, wherein they saw Utgarda-Loki, laden hand and foot with enormous chains. Each of his reeking hairs was as large and stiff as a spear of cornel. Thorkill (his companions lending a hand), in order that his deeds might gain more credit, plucked one of these from the chin of Utgarda-Loki, who suffered it. Straightway such a noisome smell reached the bystanders, that they could not breathe without stopping their noses with their mantles.

This is an image of Loki bound near the hall on the Na-stronds in Niflhel. the sailors arrive by ship and see a hall swarming with serpents filled with iron seats (Voluspa 37). In an adjoining cavern they find a bound giant whom Saxo calls "Utgard-Loki". It is Loki himself. In Snorri's Edda, Utgard-Loki is a name used of giants who are masters of mirages, and among whom Logi (fire) is a servant. They are Surt's men. In Saxo, the name indicates a bound giant in Niflhel, so it must refer to Loki who was bound there, near the Fenris Wolf.

Saxo wrote in Denmark a generation before Snorri wrote his Edda in Iceland. Both wrote of the gods as ancient kings from the Classical world, and used the mythic poems as their sources of inspiration.
Even Voluspa places the bound Loki in proximity to the hall on the Nastronds conceptually…..
·

Voluspa: The Volva's Prophecy

  1. Bound she saw lying,
    under Hvera-lund, [Kettle-grove]
    a monstrous form,
    to Loki like.
    There sits Sigyn,
    for her consort’s sake,
    not right glad.
    Understand ye yet, or what?
  2. From the east a river falls,
    through venom dales,
    a river with knives and swords
    Slid is its name.
  3. On the north there stood,
    on Nida-fells,
    a hall of gold,
    for Sindri’s race;
    and another stood
    in Okolnir (the Not-cold),
    the Jötun's beer-hall
    named Brimir [Mimir].
  4. She saw a hall standing,
    far from the sun,
    in Náströnd (Corpse-shore);
    its doors are northward turned,
    venom-drops fall
    in through its apertures:
    entwined is that hall
    with serpent’s backs.
  5. She there saw wading
    the sluggish streams
    bloodthirsty men
    and perjurers,
    and him who the ear beguiles
    of another’s wife.
    There Nidhögg sucks
    the corpses of the dead;
    the wolf tears men.
    Understand ye yet, or what?
    ·
    It's likely that Saxo had this passage in mind when he wrote of this.
    ·
    Prose at the end of Lokasenna: After this Loki, in the likeness of a salmon, cast himself into the waterfall of Franangr, where the Æsir caught him, and bound him with the entrails of his son Nari; but his other son, Narfi, was changed into a wolf. Skadi took a venomous serpent, and fastened it up over Loki’s face. The venom trickled down from it. Sigyn, Loki’s wife, sat by, and held a basin under the venom; and when the basin was full, carried the venom out. Meanwhile the venom dropped on Loki, who shrank from it so violently that the whole earth trembled. This causes what are not called earthquakes.
    ·
    Lokasenna: Loki's Insults

Frey

  1. I see the wolf lying
    at the river´s mouth,
    until the powers perish.
    So shalt thou be bound,
    if thou art not silent,
    thou framer of evil.

Skadi

  1. Thou art merry, Loki!
    Not long wilt thou
    frisk with an unbound tail;
    for thee, on a rock´s point,
    with the entrails of thy ice-cold son,
    the gods will bind.

Loki

  1. Know, if on a rock´s point,
    with the entrails of my ice-cold son,
    the gods will bind me,
    that first and foremost
    I was at the slaying,
    when we assailed Thiassi.

Baldur's Dreams.

Vala
“Home ride thou, Odin!
and exult.
Thus shall never more
man again visit me,
until Loki free
from his bonds escapes,
and Ragnarök
all—destroying comes.”

We find references to the episode of Thor in Skyrmir's glove in Lokasenna and in Harbardsljod, there we learn his name is Fjalar. When Odin married Gunnlod and stole the mead back, he was at Fjalar's (Havamal 13-14). We can identify them with Suttungs sons, who are Surt's men, in Surts sokkdalir (Surt's sunken dales) in the deep south, corresponding to the world of fire in the early days.

Harbardsljod .

Harbard

  1. Thor has strength overmuch,
    but courage none;
    from cowardice and fear,
    thou wast crammed into a glove,
    and hardly thoughtest thou was Thor.
    Thou durst not then,
    through thy terror,
    either sneeze or cough,
    lest Fjalar might hear it.
    ·
    Havamal .
  2. Oblivion’s heron ‘tis called
    that over liquor hovers,
    he steals the minds of men.
    With this bird’s pinions
    I was fettered
    in Gunnlöds dwelling.
  3. Drunk I was,
    I was over-drunk,
    at that cunning Fjalar’s.
    It’s the best drunkenness,
    when every one after it
    regains his reason.

According to Havamal 104-110, Odin arrives at Gunnlod's in disguise ("in the well-purchased appearance) and plays the part of the expected groom. he marries Gunnlod and is served mead on the golden seat as the guest of honor. At night, when he is alone with her, he escapes with the stolen mead. For this, the giants call him Bolverkr (Evil-worker). Snorri reverses this and jumbles the retelling. In his version Suttung and Fjalar are separate beings, and Odin sneaks into Gunnlod's cave, calling himself Bolverkr.

At some point, Fjalar and his men lure Thor to their world, and test his strength. They use illusions to fool him. But come away fearing Thor's great strength. Thus, when Odin went in disguise and fooled them into thinking he was someone else, he used their own tactics against them, ironically.

William P Reeves, 2021