Odin has been fatally wounded by a weapon of entropy, and Ysgard declares open war on Limbo. Baldur and Jarnskeggi agree on one course of action to save the Allfather’s life. The heroes of Breidablik, who have proven themselves time and again, must journey to the Gates of the Moon and consult Selûne for an answer. Our Lady of Silver is venerated as a goddess of stars, navigation, questers, and goodly lycanthropes. Since she and her sister Shar coalesced out of the material of Realmspace after it was created by Ao, it stands to reason that either of the two might know how to heal Odin’s entropic wound.
Travel to the Gates of the Moon can be accomplished in various ways, but Jarnskeggi suggests the Infinite Staircase. Every full moon on Ysgard, a portal opens up to the Infinite Staircase, which is said to connect to every city in every plane and perhaps in every time. The stairways, invisible to ordinary people, can only be seen properly by gods or by very powerful mortals. Baldur goes with the companions to make the entrance known to them. This entrance appears as a nondescript cellar door outside an abandoned farmhouse a few miles from Breidablik. Baldur instructs the party to climb 29 flights of stairs to reach the Gates of the Moon, then he returns to his hall.
After some experimentation, the party discovers that the door needs to be opened all the way and then closed halfway again so that the door itself is vertical. This reveals a portal that hadn’t been there before. Beyond the portal lies a seemingly endless ocean of luminous liquid light under an equally boundless night sky full of stars and Toril’s moon. There are no stairs; Baldur was obviously wrong. In the middle of the ocean is a island of stone with a magnificent silver acropolis at its crown. Krissy recognizes this place from stories she read as a little girl — Selûne's acropolis is known as Argentil. Bryta, Xenephon, T'chon, Silversac Sam, and Krissy all step through the portal.
As the companions marvel at this strange new realm, standing as they are upon the ocean itself, a trio of beings resembling human women but composed of moonlight and flame descends from the star-lit sky to alight upon the waters ahead. Illumination shines visibly in their eyes, their hair, and even from the tips of their fingers. Krissy remembers that these beings are known as shards — petitioners of this realm. The shards are friendly and accommodating, speaking with Bryta in the language of Celestials. The valkyrie explains Odin's situation and the reason for her presence in this realm. The shards generously lead the adventurers toward the acropolis.
Argentil is a gigantic palace, its entire surface, inside and out, glistening with polished silver. The entrance is watched by a single golem made out of whitish silver. The path through the palace is long and awe-inspiring, as only the home of a deity can be. Finally, their escort brings them to a set of huge, intimidating doors, in the silver surface of which is carved the symbol of infinity. When Bryta approaches the doors, the symbol leaps off the surface. A lillend with a golden mask materializes behind the symbol. She welcomes the visitors, and after speaking with Bryta for a bit, allows them into Selûne's inner sanctum.
When the adventurers step through the doors, they find themselves standing under a seemingly endless night sky. Looking back, the doors are gone, the lillend is gone, the acropolis is gone — only a shallow lake, about ankle deep, and the night sky, remain. Between the silver moonlight and the stars, countless fireflies flit about in the air. And there, sitting in the slight depths, is Selûne. She appears as a young girl with white hair, fair white skin, white robes, and an innocent, relaxed expression on her soft face. Though Bryta has many questions, Selûne responds only with the following poem:
Flies of the garden’s roses, O what din
Has scattered those flushed petals in an hour,
And the pantries of all the cottages thinned,
What Stygian wind,
O sad lord archon banished to a grave?
Tercival has out-blushed the roses: bound
As all the feasts of the world’s delight.
And every rose of joy has been downed,
And for sweet shame is bound;
Sweet meal being spoiled in the pure fool’s sight.
And with that, a host of fireflies descends upon Selûne, one by one completely enveloping her, so that all the characters can see is their blinding luminescence. A gust of wind picks up, dispersing the fireflies, and Selûne is gone.
T'chon thinks her poem references the gluttonous Lord of the Flies, Ba‘al Zəbûb. Xenephon recognizes the famous paladin named Alek Tercival, long thought to be dead, and the Stygian winds of Pandemonium. Krissy wonders if Selûne is suggesting that Tercival is not really dead, that maybe he is being held prisoner by Ba‘al Zəbûb in Pandemonium. If so, then this is the only lead the adventurers have in discovering a cure for Odin’s wound. But getting to Pandemonium is easier said than done.
They return to the Infinite Staircase. When the party first begins their ascent, the staircase looks like a spiraling silver stairway entwined with ivy. The first landing is a 200-foot disc, with numerous other staircases, all of different appearance and composition, extending off like tentacles. Walls are no longer visible; instead, each stair disappears into hazy darkness. Sometimes these staircases are oriented in different directions from the one that the viewer stands upon — up, down, left, and right are not the same for travelers on those stairs. During the course of their trip, they cross over many types of stairs — straight, wooden staircases, spiral stairs made of metal, winding curved stairs of stone, and more.
For the most part, travelers on the Infinite Staircase find it to be a lonely, desolate place. Usually, one could climb the stairs a whole day and never see another soul. However, today is not so lucky. An ettercap and four giant spiders wandered in from some doorway long ago and constructed a web between two portions of demolished staircase — the gap being about 30ft across.
Krissy instinctively shoots at one of the spiders with her crossbow, starting the fight. As the other three scuttle onto the stairway, the companions draw their weapons and burst into the melee. Bryta flourishes her luminous wings and flies across the breach to engage the ettercap. Silversac Sam bellows a warcry and rages, chopping with his mighty greataxe. Xenephon hurls sacred fire at his arachnid foes. T'chon flies up high and attacks with precise longbow shots. The spiders prove to be more deadly than expected; after the combat the companions take a long rest.
On her watch, while her friends sleep all around her, Krissy spies a winged gorilla a couple flights up. She scrambles to her feet, but when the creature realizes that it's been spotted, it turns and flees into a heavy iron door above. After everyone else wakes up, the rogue informs them what had transpired on her watch. T'chon recognizes the winged gorilla as a derhii, a vicious and highly intelligent demon from Limbo. Xenephon thinks maybe this creature was spying on them for the slaad. In any case, the party packs up their belongings and heads out again.
The next couple doors do not look appealing. First the party checks out the iron door that the derhii had fled into. Beyond is a portal to the cold, snowy Iron Wastes, the 23rd layer of the Abyss. The second door they open is made of brass, and when Xenephon opens it, he is assaulted by hot air and flames. The azer recognizes the Plane of Fire and the City of Brass in there. Krissy convinces her friends to enter the third door, which is beautifully carved oak endowed with brightly colored flowers and leads to Arvandor.
Within this portal the companions see a beautiful female faerie, garbed in noble attire, and three sprite bodyguards standing in a grove on one of Grandfather Oak’s huge branches, surrounded by leaf pods. Sunlight shines upon one of those leaf pods, which the noble faerie plucks up into her graceful arms. Immediately after she chooses a pod, evil darklings and quicklings from the Unseelie Court swoop in to attack! The female faerie hides behind her bodyguards, who do their best to protect her, but it looks like they'll soon be overwhelmed by the sheer number of evil fey. Krissy and her companions leap in to help.
Even as Bryta, Xenephon, T'chon, Silversac Sam, and Krissy defeat their Unseelie foes, a veritable army of dark faeries approaches, riding upon giant bees. The noble faerie woman begs them to flee with her — the fate of all good faeries lies in this leaf pod, and it cannot fall into the wrong hands. A kaleidoscope of giant butterflies bursts out from underneath the branch. Krissy is the first to jump onto one. Her companions follow a second later. And so they all fly off on their butterflies, the Unseelie in hot pursuit.
Finally they make it to safety, a grove at the base of Grandfather Oak, with a peaceful pond and weeping willow tree. The noble faerie woman alights upon a mossy rock and introduces herself as Titania, Queen of the Seelie Court. She explains that the pixies and sprites of her Court have recently been falling ill. She can’t explain why, though she has sent a few brave faeries out in search of an answer. She suspects that “the balance” is in jeopardy. Perhaps there is too much evil in the multiverse, or too much chaos. This leaf pod that she plucked from the grove is an unborn faerie. Fewer of their kind are being born as well, which really concerns her. Titania pleads for the adventurers to help get to the bottom of this. When they agree, she gifts them with a ring of shooting stars, and she gives Krissy the leaf pod, instructing the rogue to protect it with her life. Titania and the remainder of her faeries must leave now — it is no longer safe here with the Unseelie faeries swarming the area.
The adventurers head back up Grandfather Oak to meet with the elves, gathering information and buying, selling, and trading their loot. After the Unseelie have moved on, the plan is to return to the Infinite Staircase portal and continue their quest.