Keep of the Eternal Sun

The Keep of the Eternal Sun

Former realm of Aumanator

Location: Mechanus

The Keep of the Eternal Sun lies dormant and strange, an abandoned cog rotating slowly amongst the infinite clockwork of Mechanus. Once, it was the resplendent domain of Amaunator, an ancient power of law, time, and the eternal cycle of the sun. His four celestial suns danced in perfect synchrony through the skies of the cog, shining across all of the discs of the sector, keeping time and casting patterns of light and shadow in a predictable—if complex—mathematical pattern. But that harmony ended when Amaunator fell. After the prime kingdom of Netheril was destroyed, worship of the Keeper of the Eternal Sun dwindled, as his faithful turned away in anger at his lack of intervention. Without enough worshippers to sustain his divinity, the Keeper of Lawful Radiance was drawn into the Astral, leaving his realm untended and his suns without their master.

A Realm Unmoored by Divinity

When Amaunator was cast into the dead-book, the Keep was cast adrift from its divine purpose. The four suns—golden, red, white, and black—still orbit the cog, but their movements have become erratic, occasionally accelerating or decelerating without reason, as though struggling to maintain their symmetrical pattern without divine guidance. Their light still radiates across the cog, but where the sector used to be bathed in the light of all four suns continuously, now the balance has been disrupted, causing the light from one sun or other to dominate at different times, and leaving vast sections in eerie twilight.

The four coloured suns of the realm are said to each be embodiments of different kinds of light that the suns of the prime radiate down. The white sun represents the illuminating power of light, chasing away the darkness and revealing the hidden. However, this is a cold light, with none of the warmth-giving properties of a prime sun. Turns out that heat instead comes from the red sun, which used to radiate a gentle light which bathed the realm in the perfect temperature. Now however its orbit means that some times the cog is scorched with fearsome heat and others it is frigid cold.

The golden sun radiates the kind of light that encourages plants to thrive. The realm used to produce the perfect amount of food to support the surrounding sector, but the erratic golden light now means that some nearby cogs are choked with weeds and foliage, while others are sterile and barren. Finally the black sun radiates a strange light that appears like darkness to normal mortal eyes. However, to the more sensitive folks of the underground, dwarves and elves and the like, this achromatic light is plain as day—chant goes that it that can penetrate even the deepest places, and is what’s responsible for darkvision working. Whether the faltering nature of the realm has implications for bashers who rely on dark light to see in their underground lairs, only time will tell.

The Keep itself is a haunting place. Four massive spires of golden and mirror-smooth steel remain the only evidence of Amaunator’s former dominion, their once-glowing runes now flickering erratically. The architecture reflects the power’s obsession with symmetry and order: overlapping concentric rings, arches that perfectly frame the suns during their travels, and corridors that endlessly echo with the forgotten dreams of an absent god. The air feels oppressive, as though the cog itself is mourning its abandonment. In some parts of the Keep, plants and creatures which used to bask in the sun’s perfection have twisted into strange, haunted forms, surviving in the liminal gaps between light and shadow.

The Inevitables and the Power of the Suns

The enigmatic inevitables, Mechanus’s enforcers of law, have not ignored the energy vacuum left behind. In recent years they have turned their focus to the four suns, attempting to harness what is left of their waning energy to fuel their own unfathomable technologies. Chant from planewalkers tells of giant reflective arrays and scintillating engines being constructed within the cog’s lower reaches. Some claim the inevitables seek to stabilise the erratic paths of the suns, hoping to restore their lawful patterns to prevent the cog’s collapse. Others suggest more unsettling motives: the inevitables may be experimenting with the fusion of radiant energy and Mechanus’s pure law to create new constructs, blending light and machinery into unprecedented forms of sentient order.

One of the most persistent rumours involves a new type of inevitable, dubbed the solumite, said to be powered directly by fragments of solar energy. These constructs are described as beings of glowing metal and liquid light, their forms constantly shifting between solid and radiant states. What role these beings might fulfil in the hierarchy of Mechanus, or indeed whether they even truly exist or are just the fevered imaginings of a drunken Guvner, no one has yet confirmed.

The Mysteries of the Keep

The Keep of the Eternal Sun has become something of a magnet for both scholars and scavengers seeking to take advantage of its mysteries. Some hope to find remnants of Amaunator’s power, believing that lost godshards of the fallen deity’s divinity might still linger in the heart of his abandoned realm. Others are drawn by the strange artefacts created by the inevitables, fragments of solar machinery that hum with energy. But the realm is perilous. The light from the suns is not consistent, and exposure to their rays can cause unpredictable transformations—some develop burnished brass skin and resistance to heat, while others are left blind or with skin bleached white by the rays.

There are also whispers that a splinter group of rogue modrons, exiled by their race and disillusioned with Primus’s rigid caste system, is said to have taken refuge in the Keep, attempting to channel the suns’ chaotic energy into weapons that could challenge Mechanus’s order. These rogues, calling themselves the Luminaries, view Amaunator’s fall as a sign that even powers are not immune to entropy, and they seek to usher in a new paradigm where order must account for and somehow coexist with a little bit of chaos.

The Keep remains an enigma. Meanwhile, Amaunator’s godcorpse has vanished from the Astral graveyard. Chant goes he’s been reborn as Lathander, or perhaps he always was the Morninglord all along—but for whatever reason the Keep of the Eternal Sun still remains unclaimed. Perhaps Aumanator is gathering his strength to retake it and shift it to another plane. Or perhaps it truly is abandoned. I mean, the chant has been wrong before…

Canonical Sources: On Hallowed Ground [2e] p182; https://forgottenrealms.fandom.com/wiki/Amaunator. Canonwatch: None of the sources I could find say much about this realm beyond its name and the died-and-rose-again story of Aumanator, so the rest of the detail here is homebrewed to fit.

Source: Jon Winter-Holt