A few months have passed since the heroes saved Fallcrest from an undead-creating plague that was killing off the population. They have been rewarded for their service, achieving the rank of Journeyman Warden; this means they have been given authority over a group of Novice Wardens. Under their control, the novices managed to raid the lair of a cult of Zehir, kill most of the cultists, and capture the cult leader. Warden Captain Garreth was also promoted, to the rank of Lord Warden of Fallcrest; the death of Lord Warden Markhelay (and the fact that his attempted resurrection failed) left a power vacuum that needed to be filled. In addition, the Demesne has completed a major project: the Lightning Rail. While not much faster than a riding horse, the Lightning Rail–a vehicle powered by a bound elemental and held a few feet above the ground by magical conductor stones–allows for the transportation of large groups of people and quantities of goods in relative safety and comfort. Best of all, the Lightning Rail can travel non-stop, and is cheap to travel on. Currently the Rail connects Bastion, the capitol city, to a few other major towns and cities (such as Fallcrest), but more lines are planned.
In the interim months, Chance spoke to Areth, a man that the party saved from a medusa not too long ago. Areth claimed to have been good friends with Chance's father. What's more, he told Chance of two others like him, both created by his father (and therefore, are his brothers). The first is Judgment, the warforged assassin that the party failed to save Markhelay from. The second is a hermit named Book, whose whereabouts are unknown.
Silus, feeling guilty over the release of the devil of smoke and shadow from Vashtarborg, contacts a number of people to gather information about possible cult activity. In addition, he pores over some of the books that he took from Vashtarborg on demonology and infernal pacts, and learns that, in order to bind and banish the devil, he must know its true name. He contacts his patron, an infernal being himself, using a special summoning ritual, and proceeds to wait for a response.
Back in present time, the party learns that they have a client. Meeting back at the office in Fallcrest, they find out that the client is none other than Isolde, the priestess of the Raven Queen and Silus's ex-lover. She is both grateful and impressed at their saving her from the medusa and saving Fallcrest from the machinations of the Prince of Dusk, and wants to hire them to find something for her.
She tells them that she wants an artifact, the Ashen Crown. The Crown is sacred to her order because of its power over death and the dead. What's more, she fears that it might fall into the hands of the followers of Vecna, the lich-god, and she believes that this would be a catastrophic loss. She offers the heroes 2000 gold pieces up front, with another 2000 upon delivery of the Crown. She also tells them that finding the Crown might be complicated, as it was sundered into five pieces thousands of years ago, and each piece was given to a powerful goblin warlord.
Isolde knows only where the first piece is: Ashurta's Blade lies within Ashurta's Tomb, under the city of Bastion. The party accepts, and makes arrangements to ride the Lightning Rail to Bastion the next day, on the same coach that will take the leader of the cult of Zehir to Bastion for trial and imprisonment.
Most of the trip is uneventful; eight Novice Wardens have been assigned to guard the prisoner, so the heroes have little to do. Just the same, Silus sleeps in the prison car with the on-duty novices. He wakes up toward the end of the first day of travel to find all of the novices in the car unconscious, the prison door open, and the prisoner gone. He goes to the Wardens' passenger car and relays the news. Shortly after, Shava hears people walking on the roof of the car, so the party climbs the ladder leading to the roof.
On the roof they find the cult leader, along with five of his followers and two archers riding wyverns, flying alongside the coach. An airship is also in the distance, and is coming closer. Battle ensues. Shava shoots at the wyverns from within the coach while Chance, Kraygin, Sredni, and Silus take the fight to the roof. One of the wyverns goes down quickly, taking its rider with it, and most of the cultists are dead before long. The cult leader roots everyone in place with magical snake-like constructs of energy, and the remaining cultists press the attack.
Shortly after, the airship arrives, carrying five more cultists. One of them lowers a rope ladder and jumps down onto the coach while the others remain aboard the airship, keeping its pace with the Lightning Rail coach and manning mounted ballistae. The remaining wyvern lands on the roof of the coach and attacks Kraygin, but Kraygin pays it back by ripping one of its teeth out of its mouth in a brutal fashion. Chance then knocks its rider off, after which Kraygin mounts the wyvern and attempts to wrest control of it.
The rest of the party busies itself throwing cultists off the coach, while the cult leader climbs the ladder onto the airship. Sredni and Silus pursue him, as does Kraygin (mounted on the wyvern), though Sredni is knocked off the ladder by the cult leader. While Kraygin is making short work of the airship's crew, though, Chance is knocked off of the coach by one of the cultists! He falls and is injured, but survives the fall; the coach, however, is far ahead of him now. Luckily, Kraygin and Silus are now on the airship alone, the wyvern having flown away and the cultists having been killed or thrown off by the out-of-control airship. They are able to rescue Chance, and the three of them try to catch up with the coach.
Back on the coach, the cult leader (who was thrown off the airship and onto the coach) and one of his cronies are battling Sredni and Shava. Sredni is badly injured and almost falls off of the coach, but manages to swing inside it and rallies the Warden Novices to follow him back into battle. Between the four novices and Sredni and Shava, they manage to kill the last cultist and subdue the cult leader once more. They order the coach's driver to stop the coach so the airship can catch up. Then, they bring the cult leader aboard the ship, along with all eight of the novices, and fly the ship to Bastion.
During the trip, Silus's patron comes to him in a dream. Silus tells him that he wants to banish the smoke and shadow devil, and his patron strikes a bargain with him. It turns out that Silus's patron wants someone dead, and that person has an object that Silus needs to accomplish his task. The target is known as the Demon King, and is a petty despot living in a fortress in the Tribelands of the Dragon. Apparently, a secret entrance to his fortress opens during the full moon, which is in two weeks.
The airship eventually arrives at Bastion, and docks at the Citadel, the headquarters of the Wardens. The party deposits the prisoner and takes some of their crew with them out to investigate and try to find Ashurta's Tomb. They talk to a surly dwarf named Molric who, after some coercion, reveals the location of its entrance. They then talk to a hobgoblin priest of Kord named Oolakki, who confirms Molric's story and gives them some background on the Tomb. He tells them to be careful, to respect the Tomb, and to clear out the aberrant infestation within it.
The party descends into the sewers and finds a tunnel that leads to what was once an open-air courtyard, but is now an underground chamber. In the center is a pile of skulls, and when the party investigates it they find two things: a magic die and a scrap of leather with a cryptic symbol on it. The calm doesn't last long, though; Kraygin explores a side tunnel and is immediately attacked by a carrion crawler. The rest of the part is ambushed by a second carrion crawler, as well as two swarms of stirges and a dire stirge, all of which seem to have been warped in some way by some corrupting influence. A skull wreathed in shadow also starts to levitate and fire ghostly beams at the party. A short battle ensues, and it looks like some of the party's companions will die, but eventually all of the monsters are killed without any fatalities on the heroes' side.
The party now faces the entrance to Ashurta's Tomb, the first step on their journey to find and reassemble the Ashen Crown.