After the battle of Augustana, Dormarion tasked the council with slipping through Cheliax's borders to sabotage their defenses. The archdukes and generals who escaped this battle are expected to regroup in Citadel Krane, a Hellknight headquarters overlooking the southeastern border of Cheliax and the ducal capital of Ostenso. The council's instructions are to reach Citadel Krane, and use four scrolls of Symbol of Sealing to seal the entrances to the citadel, trapping the armies' commanders inside while the Commonwealth army makes its first strike into Chelish territory.
Aldeberan and Narsius disguise themselves as retreating Chelish soldiers, and thus monitor the plans of the fleeing army. The more conspicuous members of the council slip through the mountains along the border, avoiding human patrols who would doubtless call the alarm for a catwoman, halfling and giant spider.
Once they arrive in Ostenso, Aldeberan makes contact with a member of the Twilight Talons, Andoran's espionage wing, and she informs him of some details of the citadel and potential allies in the region. In particular, the Bellflower Network who smuggle halfling slaves to freedom, and the Glorious Reclamation who run a guerilla force of paladins within southeastern Cheliax. Unfortunately, on the tight schedule that the council must keep, they may not have time to meet with these other allies before the invasion.
After this meeting, Aldeberan and Narsius find a safe place to magically look in on the other half of the party during wha they have dubbed Scry Noon. Eora audibly describes their location and guides Aldeberan and Narsius to them. After this, the group sneaks through the woods to Citadel Krane.
They reconnoiter the citadel, first with an invisible Samara and then with a magically shrunken homunculus courtesy of Narsius. During their reconnaissance, they notice a prison in the first basement level, and a rune inscribed door a the second basement level. They also discover that the dwarven Master of Blades Tros Gharvost might be amenable to their cause. Finally, they learn that at dawn the next morning, a Hellknight recruitment ritual will place many high-ranking observers in one of the basement chambers.
Armed with this knowledge, they get some much needed rest in a clearing nearby. In the wee hours the morning, Ktihdi is awoken by an armored man wandering into their camp. He reveals himself to be a paladin of the Glorious Reclamation, informed of their presence by the Twilight Talon spy. He offers to bring his fellow paladins as support for their operation, and the group suggests that they might be most useful in shepherding away the released prisoners.
Already awake, the party decides to finalize the preparations for their operation. Just as they're finishing up, they hear a carriage driving down the nearby road, towards the citadel. The follow the carriage to see who emerges. They see several men in military uniforms, two women, all quite aristocratic, but what most strikes them is one large, black-haired man who everyone is calling General. Aldeberan recognized this as Gorthoklek, the pit fiend who has adviser all the heads of House Thrune.
Undettered, the party continues their plan, Ktihdi and Eora split off and plant packets of Narsius's bombs at key locations around the structure of the citadel. The rest of the council follows the party of dignitaries into the citadel (invisible of course) and down the to lowest basement level. One robed dignitary asks to see the Gallery, and Samara and Narsius slip in behind him to discover one of the largest depositories of magical and divine artifacts in the world: the Godless Gallery. Tossing everything they see into a handy haversack, they rejoin Aldeberan and Ktihdi who are keeping watch on the dignitaries preparing to watch The Test. Once the attendants have sealed the door so the test can begin, Samara and Eroa stab the attendants to they won't be disturbed. The party then activates a Symbol of Sealing on the door, preventing it from opening for 12 hours. The party then heads upstairs to free the prisoners (those who don't seem too dangerous) and Aldeberan goes to negotiate with Tros Gharvost to change his order's allegiance or watch it be destroyed. After some convincing he relents, and ushers his subordinates outside.
With all the Hellknights outside (aside from those locked in the basement), the party detonates the changes and collapses the building. The Glorious Reclamation take this as their signal, and swoop in to take the Hellknights prisoner. In one case this swooping is literal, as their Lord Mashal Alexandretta rides in on the back of a gold dragon, cowing any Hellknights who considered resistance.
With their generals trapped and the local Hellknights neutralized, the initial invasion of Cheliax by the Commonwealth goes off without a hitch, particularly with a gold dragon flying over the battle striking fear in the hearts of those pledged to Hell.