The Vanishing of Merchant's Lane
The Vanishing of Merchant's Lane
A series of midnight disappearances has gripped Mysterious Town, all occurring within a single block. The party must uncover whether the culprit is a criminal syndicate, a supernatural entity, or something far stranger—before the town's economy collapses and panic spreads to the outlying farmlands.
Read Aloud
You sit nursing your ale at the Cracked Flagon, a tavern that reeks of spilled mead and stale bread, when a nervous messenger slips into the booth across from you. His fingers tremble as he slides a sealed letter across the table—the wax bears the seal of Magistrate Aldous Thorne. You hear murmurs from other patrons: three merchants vanished without trace in five nights, all from Merchant's Lane. The tavern keeper refuses to venture there after dark, and a palpable dread hangs over the town like morning fog.
Description
The party is summoned by Magistrate Thorne via messenger. They're hired to investigate the disappearances from Merchant's Lane over the past five nights. The Magistrate fears a criminal syndicate, but the disappearances are too clean, too organized. No signs of struggle, no ransom demands. The first victim was Cassian Hale, a silk merchant. The second, Emilia Voss, a jeweler. The third, Yoren Kess, a moneylender. All three vanished between midnight and dawn. The Magistrate offers 150 gold each for solving the case within three days, plus lodging at the Gilded Lute (the town's finest inn). The party should learn that Thorne himself discovered the first body—or rather, didn't find one at all. When he checked Hale's shop the morning after, the merchant was gone, his ledgers scattered, and the back door left ajar. The Town Guard has already searched the surrounding streets and found nothing.
DM Notes
Let the party ask questions. Thorne is fearful but cooperative. A DC 12 Insight check reveals he's hiding something—he was meeting with Hale the night the merchant disappeared, discussing "a private matter." If pressed, he admits Hale owed him coin for a past favor and was reluctant to repay. This is a red herring: Thorne is innocent, but his presence at the scene looks suspicious. A DC 14 Investigation check on the letter itself reveals it was written in haste, with crossed-out words. Reward curiosity with minor clues. The party should head to Merchant's Lane to investigate the scenes directly. Thorne provides a Town Guard escort (reluctant, low morale).
Read Aloud
Merchant's Lane is a narrow cobblestone street lined with shuttered storefronts and darkened windows. The smell of old coin, leather, and something sickly-sweet—like rotting fruit mixed with copper—hangs heavy in the air. Three buildings stand out: Hale's Silks, the jeweler's shop (Voss & Co.), and Kess Moneylending. Each shop bears fresh scorch marks on the doorframes and window sills, as if something hot has been pressed against the wood. Most eerie: all three doors are sealed from the outside with iron bars and heavy chains, yet the chains show no signs of rust or weathering. They were installed recently, within the past day.
Description
The party arrives at Merchant's Lane in the late afternoon. The street is eerily quiet. The Guard escort points out the three vanished merchants' shops and retreats to a safe distance. The party has time to search the exterior before nightfall. Each shop is chained shut. A DC 13 Perception check notices the scorch marks—they form a pattern on the ground in front of each shop: a three-foot-wide semicircle, as if something large and hot emerged from beneath the cobblestones. A DC 15 Arcana check identifies the residue as infernal in origin (sulfur, charred bone, necrotic essence). A DC 12 Investigation check on the chains reveals they were installed by a professional—quality work, fitted to the door hinges with precision. The locksmith's mark on the chain links points to "Garrett's Iron Works," a shop on the opposite side of town. The party can force the chains (DC 16 Strength check), pick the locks (DC 16 Sleight of Hand), or approach Garrett for information. If they visit Garrett, he'll admit he made the chains at the behest of an unknown client who paid triple his usual rate and insisted on anonymity. The payment was in coin that Garrett swears "felt wrong"—heavy, cold, and bearing no visible markings.
DM Notes
The scorch marks are the party's first hint of a supernatural threat. Don't reveal the nature of the threat yet. If the party forces entry into a shop, they'll find it completely empty—no signs of struggle, no goods, nothing but bare shelves and a lingering smell of brimstone. A DC 14 Investigation check on the floors reveals thin cracks in the stone, radiating outward from the back room of each shop. These cracks match no structural pattern and seem to follow a purpose. The back rooms all contain trap doors (DC 16 Perception to notice in the dim light). The trap doors are sealed from below—locked from underneath, impossible to open from above. If the party rests here, read Encounter 1 during the night watch. Otherwise, they'll encounter the threat tomorrow evening (Scene 3).
Read Aloud
You're keeping watch over Merchant's Lane as the sun dips below the horizon. The air grows cold—unaturally so, as if the warmth is being drawn from the world itself. Then you hear it: a deep, rhythmic scraping sound emanating from beneath the cobblestones, directly in front of Kess Moneylending. The sound is accompanied by a sickly-sweet smell of sulfur and burning flesh. Cracks spider-web across the street, glowing faintly red from below. The ground begins to heave. Something massive is forcing its way up from underneath the town.
Description
This is the climactic encounter of the session. A powerful infernal entity—a Summoned Devil (Bearded Devil, CR 3, acting as a servitor)—erupts from beneath Merchant's Lane, followed by three Imps (CR 1 each). The party witnesses the arrival of these creatures. The Bearded Devil is bleeding from a fresh wound on its arm—evidence that it's been enslaved or bound through magic. The Imps are carrying chains and shackles of infernal origin. The creatures have come to claim their fourth victim: a young apprentice from Hale's Silks who was hiding in the cellar, terrified and waiting for rescue. The girl is not the merchants—she's leverage. An NPC named Mira Hale, the merchant's daughter. The devil's master sent these creatures to collect the merchants and Mira as payment for a debt. The party must decide whether to fight, negotiate, or pursue the infernal creatures. The floor beneath Merchant's Lane is unstable—portions of the street are collapsing into a cavern below. This is the infernal rift through which the creatures are emerging. The encounter takes place on unstable terrain with multiple hazards.
DM Notes
This is a Hard encounter for a party of 2 level-7 adventurers (Fighter and Wizard). Use action economy carefully: the Bearded Devil makes 2 attacks per turn (beard and glaive), and the three Imps use Invisibility and Sneak Attack tactics. The Imps should focus on the Wizard (lower AC, single-target threat). The Bearded Devil should engage the Fighter in melee, with the goal of restraining or grappling to prevent spell casting from the Wizard. If the Wizard uses AoE spells (Fireball, Lightning Bolt), the Imps will scatter and use cover. The unstable terrain forces movement: each round, one section of floor collapses (randomly determined). The party can make a DC 14 Dexterity saving throw to avoid falling 10 feet into the cavern below (minor damage, but disorienting). The infernal rift is the key to the mystery: it's a controlled portal. If the party defeats the creatures or forces them to retreat, the rift begins to collapse. The party can attempt to close it (DC 16 Arcana check) or let it seal itself over 1d4 minutes. Closing it early grants advantage on all remaining saving throws in the encounter.
Read Aloud
As the rift collapses and the infernal glow fades, you stand amid the rubble of Merchant's Lane. Beneath the broken cobblestones lies a cavern roughly forty feet down. In its depths, you spot three shapes—the missing merchants, suspended in crystal cocoons. They're still alive, you sense, but trapped in some form of magical stasis. A fourth cocoon is empty, its crystalline shell shattered. A small iron key lies on a ledge just visible from the street level, its handle shaped like a demon's skull.
Description
The party has defeated the immediate threat. Now comes the investigation of the cavern below. The merchants can be rescued (they require a DC 13 Medicine check to safely extract from the cocoons without harming them). The empty cocoon belonged to a fourth victim—a wealthy landowner named Bertram Crane—who was successfully taken by the infernal creatures before the party arrived. The skull-key opens a small iron strongbox also visible in the cavern. Inside the strongbox are three documents: (1) A contract written in infernal script, detailing a debt of 5,000 gold pieces owed by Magistrate Thorne to a demon lord. The contract stipulates that if the debt is not repaid by the new moon, the creditor may collect "souls or gold in equal measure." (2) A ledger naming all the merchants and Crane as co-signatories to Thorne's debt—they were witnesses to a dark pact made seven years ago. (3) A letter from Thorne to an unknown recipient, dated three days ago, stating: "The time is upon us. The contract comes due. I have arranged for the chain-smith to seal the merchants' shops. When the collectors arrive, they will find only locked doors. The merchants will be taken, and the blame will fall upon brigands or worse. My debt will be paid in bodies, not coin. May the gods forgive me."
DM Notes
This is the revelation moment. Magistrate Thorne is the true antagonist—not the merchants, not the infernal creatures, but Thorne himself, who orchestrated the disappearances to satisfy an infernal debt. The merchants were witnesses to his pact; their removal ensures they cannot testify. The party now faces a moral choice: confront Thorne, expose him publicly (causing panic), or use the documents as leverage. Thorne will initially deny everything, then attempt to flee or bargain. If confronted directly at the magistrate's office, he'll offer the party gold and a promise to resign quietly if they destroy the documents. This is an investigation mystery, not a combat encounter. Reward clever questioning and thorough searching. The third merchant, Crane, is presumed taken to the Infernal Plane and is likely lost—this adds tragedy to the resolution and suggests future sessions could involve planar travel to rescue him.
Monsters
Tactics
The Bearded Devil enters combat aggressively, using its Multiattack to focus on the Fighter (target AC and HP). Its Glaive has 10-foot reach, allowing it to maintain distance. On its second turn, it uses its Beard attack to attempt grappling the Fighter, restricting movement and preventing bonus actions. The three Imps use their Invisibility action to vanish on their first turn, then reappear to use Sneak Attack against the Wizard (lowest AC, easier to surprise). If an Imp is hit, it becomes visible but will retreat and re-cast Invisibility on the next turn. The Bearded Devil ignores the Imps' positioning and focuses purely on melee combat with the Fighter. If the Wizard casts AoE spells, the Imps will use the unstable terrain to scatter and gain half-cover. The creatures will attempt to retrieve Mira (currently unconscious on the ground nearby) and drag her toward the infernal rift. If 2+ creatures are defeated, the survivors will attempt to retreat through the rift.
Terrain
Merchant's Lane is now a collapsed ruin. The street has cracked into four distinct sections, each separated by 5-foot-wide chasms. Portions of the ground are actively collapsing: each round on initiative count 20, one random 5-foot square section collapses, becoming difficult terrain and requiring a DC 14 Dexterity saving throw for any creature in that square to avoid falling 10 feet into the cavern below (1d6 bludgeoning damage plus being knocked prone). The collapsed areas grant half-cover to creatures within them. The infernal rift itself is a 15-foot-diameter pool of glowing red energy in the center of Merchant's Lane—any creature that enters the rift must make a DC 14 Dexterity saving throw or take 3d6 fire damage and be pulled 10 feet closer to the center of the rift. The Bearded Devil is immune to this damage and can move freely through it. The Imps can use the rift as an escape route but will take the damage if forced through it.
A rolled parchment written in infernal script, bearing the seal of a demon lord and signed by Magistrate Thorne. Contains evidence of the debt and the condition that the merchants must be delivered as payment. A scholar or spellcaster fluent in infernal can translate it. This document is the key to unmasking Thorne.
An iron key shaped like a demon's skull, capable of opening any lock of infernal origin. Grants advantage on saving throws against infernal magic and spells cast by fiends while the key is held. A rare and valuable artifact. Worth 500 gold to a collector, but priceless as evidence.
A leather-bound book listing the names and seals of all merchants and landowners who witnessed Thorne's original pact. Includes the now-missing Bertram Crane. This ledger proves Thorne's motive for the disappearances.
Three sealed letters from Thorne to unknown recipients, including the one confessing his plan to sacrifice the merchants. Combined with the contract and ledger, this forms an irrefutable case against Thorne.
Among the Imps' belongings, the party finds 30 gold pieces bearing strange markings and radiating cold. These coins are payment from the infernal realm. A spellcaster can identify them as infernal in origin (DC 12 Arcana). Worth 600 gold to the right collector, but dangerous to carry—they attract infernal attention if held for more than 24 hours. The party should consider disposing of them safely.
Story Hooks
The discovery of Bertram Crane's empty cocoon suggests the landowner was successfully taken to the Infernal Plane. A future session could involve the party being hired to rescue Crane, requiring planar travel to the Nine Hells or a negotiation with the demon lord to secure his release. Additionally, the Infernal Pact Contract hints at the existence of other debt-holders in the region who may have made similar deals. Thorne's exposure could spark a regional investigation into dark pacts and hidden infernal influence in nearby towns. Finally, the question of who summoned the infernal creatures and created the rift remains partially answered—if the party chooses not to execute Thorne, he may become a recurring antagonist with connections to deeper infernal conspiracies.
Conclusion
Wrap Up
After the infernal creatures are defeated and the rift collapses, the party rescues the three merchants from their crystalline prisons. Cassian Hale, Emilia Voss, and Yoren Kess are confused but alive, emerging from magical stasis unharmed. The documents found in the cavern provide irrefutable evidence of Magistrate Thorne's guilt. The party must now decide how to handle this revelation: they can arrest Thorne formally, present the evidence publicly (causing significant upheaval in town governance), negotiate a quiet resignation with promises of secrecy, or even pursue darker justice. Mira Hale, who was hiding in the cellar all along, comes forward as a witness to her father's conversation with Thorne about the debt. The Town Guard, once the truth is revealed, will arrest Thorne on charges of conspiracy, attempted murder, and trafficking with infernal entities. The magistrate's fall from grace sends shockwaves through Mysterious Town. The merchants are grateful and offer the party 200 gold each (plus the promised 150 from the original contract). More importantly, they become powerful allies in a town suddenly without official leadership. The party is asked to temporarily oversee town security until a new magistrate can be elected, giving them considerable influence and a base of operations for future adventures.
Cliffhanger
As Thorne is led away in chains by the Town Guard, he turns back one final time and speaks a warning, his voice hollow and despairing: "You think you've won, but the contract is older than you know. I was merely the first debtor in this town. There are others... in the capital, in the merchant guilds, in the temples. The demon lord does not accept failure. Mark my words—this is not an ending. It is a beginning." With that, he is taken to the town lockup. That night, a messenger arrives at your inn bearing a sealed letter in infernal script, addressed to "The Ones Who Broke the Pact." The envelope radiates faint heat, and you can smell sulfur emanating from within.
Next Session Hooks
- Investigate the mysterious letter from the infernal realm and determine what threat or opportunity it represents
- Rescue Bertram Crane from the Infernal Plane by negotiating with the demon lord or discovering an alternative means of planar travel
- Uncover the identities of other debtors in the region who may have made similar pacts with infernal entities, and determine whether they pose a threat to the stability of the realm
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