Adventure overview and historical inspiration

The Historical Event: The Dancing Plague of 1518

In the summer of 1518, the city of Strasbourg witnessed one of the strangest outbreaks in European history. In July, a woman remembered in historical accounts as Frau Troffea reportedly stepped into the street and began dancing uncontrollably. There was apparently no music or celebration to explain her behavior. She continued for days, and within a short time other people began exhibiting the same strange compulsion. Within weeks, contemporary and later accounts described dozens, eventually perhaps hundreds, of people dancing throughout the city. Estimates vary considerably, with some accounts suggesting as many as 400 people were affected.

The afflicted did not simply dance for pleasure. Their movements were described as frantic and involuntary, with people continuing despite exhaustion, injury, hunger, and thirst. Later accounts claimed that some victims died from exhaustion, strokes, heart attacks, or other consequences of the prolonged exertion, although the exact number of deaths—and even whether the commonly repeated death toll is historically reliable—remains disputed. What is certain is that the phenomenon was serious enough to alarm the city’s civic and religious authorities.

The authorities initially had no idea what was causing the strange behavior. Physicians of the period reportedly attributed the condition to an excess of “hot blood,” reflecting the medical theories of the time. Rather than simply restraining those afflicted, the authorities adopted an extraordinary remedy: they encouraged the victims to continue dancing in the belief that the sickness could be worked out of their bodies. Stages were erected, spaces were cleared, and musicians were brought in to accompany the dancers. The remedy, unsurprisingly, did not solve the problem and may have encouraged the phenomenon to spread further.

Eventually, the authorities reversed course. Public dancing and music were restricted, and religious intervention became increasingly important. The afflicted were eventually associated with the cult of Saint Vitus and taken toward a shrine for religious healing. By September, the outbreak had subsided. Centuries later, historians and scientists have proposed numerous explanations, including ergot poisoning, neurological illness, and—most prominently—mass psychogenic illness arising from extreme social stress. Strasbourg had endured famine, disease, poverty, and other hardships in the years preceding the outbreak, making the event even more difficult to separate from the desperate conditions surrounding it. No definitive explanation has ever been established.

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The Adventure

In this fantasy adaptation, the players arrive in a city modeled after Strasbourg during an outbreak that appears remarkably similar to the historical dancing plague. People have begun suffering from a strange affliction that forces them into violent, uncontrollable movement. Some have danced until their feet are bloody; others have collapsed from exhaustion, dehydration, or injury. Physicians argue over its cause while the clergy insists that the sickness may represent divine punishment. The city’s authorities are overwhelmed, and rumors have begun to spread that a curse, a demon, or a necromancer is responsible.

The characters have been sent to investigate by a powerful Church authority from outside the local hierarchy. Their patron, Prelate Anselm Rott, is a genuinely conscientious man who knows nothing of the secret Order’s crimes and wants the characters to discover the truth. Their initial task appears straightforward: determine what is causing the sickness and prevent the outbreak from spreading. As they investigate, however, they discover that the affliction is not supernatural at all. Someone has deliberately poisoned the town’s water supply with a substance capable of producing the bizarre symptoms. The party will have to determine how the poison was introduced, where it came from, and whether someone is deliberately using the outbreak for another purpose.

Their investigation is complicated by the conditions surrounding the plague. The region is suffering from poverty, hunger, failed harvests, and disease, creating an atmosphere in which desperate people are willing to do desperate things. Early in the investigation, the party must defend the town from a band of brigands who have heard that the sickness has left it virtually defenseless. The brigands are not agents of the conspiracy; they have come from a starving village a day’s journey away hoping to steal food, valuables, and anything else they can carry home. Their attack provides both a combat encounter and a glimpse into the wider desperation of the region. Among the things the party learns afterward is that another town has suffered from the same strange sickness.

The second town provides the first major break in the mystery. Unlike the first city, the dancing has already stopped. The townspeople discovered that their well had been contaminated and sealed it, and the affliction rapidly disappeared. The players therefore begin to understand that they are dealing with a poison rather than a divine curse. Their investigation there coincides with the funeral of Matthias Veyr, an important figure within the local theocracy. The party does not initially know Veyr’s significance, but the funeral introduces them to rumors of a secret religious organization operating within the Church. They are eventually told that, because they have come from the first afflicted city, they must warn another member of this organization—Brother Aldren.

Before the party can return to the first city and warn Aldren, they are attacked by mercenaries or brigands on the road. If the characters search the mercenaries’ belongings, they may find an unfamiliar religious signet ring. Later investigation can establish its connection to Canon Severin Kessler and the secret Order; the mystery must remain solvable if the ring is never found. When they finally return to the city, they discover that they are too late: Aldren is already dead. His death appears at first to be another consequence of the dancing sickness, but the party now knows enough to recognize that the deaths are connected. Eventually they learn that Veyr and Aldren were members of an Order whose surviving members are being systematically hunted.

A suspected necromancer and his young acolyte provide an important red herring during the investigation. The acolyte has purchased materials associated with the poison, and the necromancer’s laboratory contains disturbing experiments involving corpses, fungi, toxins, and strange alchemical substances. Everything appears to point toward them until the party discovers that the acolyte has no knowledge of the murders and that the necromancer’s research was unrelated. Someone stole or obtained his research and used it to create the poison. The investigation then shifts from the supernatural to something much more deliberate: someone with knowledge of the Church and access to forbidden alchemical research is using a manufactured plague as a cover for murder.

Eventually, the party uncovers the reason. Years earlier, a scholar named Elias discovered a document that contradicted an important doctrine of the Church. The Order of the Sacred Vigil discovered the document and decided that its contents could not be allowed to become public. Elias was captured, tortured, and killed, and the document disappeared. One of the people involved was Matthias Veyr. Elias’s surviving relative eventually learned what had happened and devoted himself to finding those responsible. He tracked down Canon Severin Kessler, the Order official chiefly responsible for Elias’s capture, torture, and death. He tortured Kessler for the names of the other members of the Order and then killed him. Konrad deliberately targeted Matthias Veyr with poisoned water during the earlier outbreak in Vauclerc, killing him alongside innocent victims. The dancing plague is therefore not the ultimate objective—it is the perfect cover for a campaign of revenge. By poisoning the water, the murderer can create chaos, disguise his killings as plague deaths, and force the members of the Order to reveal themselves as they attempt to contain the crisis.

By the end of the adventure, the players should realize that they have been investigating three mysteries that are actually one: the cause of the dancing sickness, the murders of prominent Church officials, and the secret history of the Order. The murderer is unquestionably responsible for terrible crimes, but the deeper truth is uncomfortable: the original injustice that created him may have been real. The Order really did kill Elias. The Church really did suppress the document. Matthias Veyr really was involved. The final question is therefore not simply whether the players can stop the murderer, but what they will do when they discover why he became a murderer in the first place—and what the Church is still willing to do to keep the contents of that document hidden.