While the rest of the party confronts Glazhael the Cloud-chaser down below, Garrett and Larion have been asked by Esclarotta, the spirit of Skyreach, to stop the Cult from scuttling the flying fortress.
Garrett and Larion scale the treacherous ice cliffs of the Skyreach Castle. Every shudder of the glacier sends razor sharp shards of ice cascading down on top of them. Garrett tries to pick up the pace but nearly slips to his death. So they ascend slow and steady, finally arriving at a ledge facing an enormous ice cavern.
Esclarotta warns them that one of the cultists has gone inside and barricaded himself deep within, where he is sabotaging the castle. She does not know what defenses within the tomb yet remain. Larion stops an overeager Garrett from stepping on dangerous pressure plates, and they carefully avoid the trap.
Igniting a torch, they realize there are skeletons within the ice walls of the tunnel. The “honored dead,” Esclarotta calls them, servitors of her family from long ago. Not all of the dead rest easy, however, and one of them bursts out of the wall. It’s eye sockets glow with pale blue fire. Garrett kicks the skeleton into a pit where it is impaled upon an ice-bound stalagmite.
Esclarotta warns that the cultist appears to have some necromantic skill and draws on the skeletons’ fading energies to temporarily imbue Garrett short sword and Larion’s scimitar with frost energy.
Pressing deeper into the ice tunnels, they see at least three more places where skeletons burst out of the wall, but no sign of the undead. They assume the cultist has taken his reinforcements with him.
A powerful jolt runs through the castle, rending a huge crack through the tunnel floor. Garrett nearly slides into it, but is caught by Larion. Esclarotta, now manifesting as a ghostly outline of a frost giant made of swirling snowflakes, strides across the gap. She urges them to hurry, before the castle completely loses its structural integrity. Garrett leaps across and secures a rope, which proves to be quite valuable when Larion flubs his jump and has to be hauled up.
Following Esclarotta’s giant footsteps, they hurry down the tunnel to the main chamber. The enormous double doors are made of the same magically-reinforced ice, but they have an enormous bronze lock built into them 10 feet off the ground. Esclarotta warns that the device is complicated and magically warded. Garrett asks if she has a magic passcode to share, and she tells him “Not to get into the room.”
To reach the giant lock, Garrett has Larion hoist him up on his shoulders, then secures his position by driving pitons into the ice. Using his thieves’ tools and a dagger, he gets to work disabling the three stages of the lock. It is challenging at times, but it brings him back to his second story roots in Waterdeep. A few moments of effort, and the lock clicks open.
The chamber beyond is circular, featuring a gallery made of sculpted pillars made of ice that wraps around a central floor, with a large round depression in the center. The pillars and walls are etched in glowing runes, though some of the symbols flicker or lie dead. A half-orc cultist stands halfway across the giant room, fiddling with a rune using a wand that looks like a giant icicle. Two skeletons lurk in the gallery near him, and two more wait near the entrance.
The half-orc orders his skeletal minions to attack, then uses the wand to blast Garrett with a ray of freezing energy. Garrett and Larion duck into cover behind a pillar, out of view of the skeletons. Garrett notices that there are large icicles hanging from the ceiling above the half-orc. He shoots one with an arrow, sending it plunging down onto the cultist, who is wounded.
The cultist then summons forth billowing wings of greasy smoke, which he uses to fly across the room to a different rune. Garrett concocts a plan involving a bottle of oil and flaming arrows, but Larion fumbles and they end up covered in oil with a broken bottle on the ground. The plan foiled, they race out towards the cultist but slip and fall flat on the ice. They rising unsteadily, they move more carefully across the slick floor. Garrett looses another arrow directly at the cultist, wounding him.
The two closest skeletons close in, one of them wounding Garrett. The other two skeletons, still across the room, sheathe their swords in their ribcages and then draw their bows. Larrion is badly wounded by an arrow.
The half-orc cultists chuckles, then draws energy out of the rune he was meddling with. Runes flare up across the room, flashing randomly, and Garrett gets blasted by one of them. The cultist calls out in excitement that the castle is about to fall. He then flies over to the round depression at the heart of the chamber.
Growing desperate, Garrett slips Larion a healing potion and surveys the room. He picks out the largest icicles in the ceiling and shoots another arrow into it. A huge cascade of ice falls down on the half-orc, crushing him. The animated skeletons crumple into a pile of bones. But the castle starts to shake and shudder violently, the floor tilting dangerously. The runes flash on and off like warning lights.
Esclarotta announces that it is losing altitude rapidly and urges Garrett to find the wand of winter. The rogues dash to the center of the room and grab the wand from the dead hand of the half-orc. They discover that in the sunken center of the room is Esclarotta’s enormous sarcophagus, which features a marble carving of a cloud giant woman. She directs Garrett to touch the wand to a halo of runes around the head of the carving, following a particular pattern. Doing so causes the runes to stop flashing and the descent to halt.
The castle rights itself with a lurch, sending a last wave of ice tumbling down from the ceiling. The rogues manages to protect themselves, but find that the exit is buried under rubble. Esclarotta tells them that they can whisper the word “Blagothkus” into her carving’s ear to be teleported out of the room.
They appear in the control tower of Castle Skyreach, where Blagothkus is bringing the castle under control. He thanks them for saving the castle, which his rash alliance with the Cult had endangered. He promises to take the party to Waterdeep, then head north to rally an army of giants to march against the Cult when the time is right.
Garrett asks if he will help against the white dragon Glazhael, but the cloud giant lord says that their friends have already dealt with that particular wyrm. Blagothkus tells them that he has arranged for guest quarters where they can recover. Barely on their feet, the two rogues thank him for his hospitality and then stumble out of the tower once the giant summons its door.