The Clockwork Menace of Oakhaven

A 5E (2024) One-Shot for Level 3 Characters (~3 Hours)

Adventure Overview

Setting: The quiet logging village of Oakhaven.

The Hook: Silas, the village tinkerer, hasn't been seen in a week. Last night, strange mechanical dogs attacked the local tavern. The mayor is offering 150 GP for anyone who can investigate Silas's workshop and stop the machines.

DM Info (2024 Rules Note): Remind players about their Weapon Masteries and the new Heroic Inspiration rules (they can spend it to reroll a die, and lose it upon long rest).

Act 1: Blood and Brass

The party arrives in Oakhaven just as screams erupt from the village square. They see villagers fleeing from the local tavern, "The Rusty Axe".

"The heavy wooden doors of the Rusty Axe splinter outward. Three metallic beasts, resembling hounds made of rusted gears, spinning blades, and leaking oil, bound into the street. Their eyes glow with a baleful crimson light as they bare jagged, steel teeth."

Investigation (DC 12 Intelligence/Investigation): A quick glance at the hounds reveals they are crude, as if assembled in a frantic hurry. They have a makers mark: an hourglass crossed with a wrench (Silas's sigil).

Combat: The Scrap Hounds

3x Malfunctioning Watchdogs

After the hounds are defeated, Mayor Thackery approaches the party, offering the 150 GP reward. He points them toward Silas's workshop on the edge of the woods.

Act 2: The Tinkerer's Workshop

"Silas’s workshop is a stout stone building with a chimney belching black smoke. The heavy iron front door is shut tight. A complex mechanism of interlocking brass rings covers the keyhole, slowly ticking."

The Gear Lock Puzzle

The door is magically and mechanically sealed. The rings must be aligned. Above the rings is an inscription:

"I run but have no legs. I cannot be seen, but I alter everything. What am I?"
  • The Answer: Time.
  • Action: A player must speak the word "Time" out loud, or turn the rings to form an hourglass shape.
  • Skill Check Alternative: A player can attempt to pick the lock (DC 15 Dexterity / Thieves' Tools) or deduce the mechanism (DC 14 Intelligence / Arcana).
  • Failure/Trap: If they guess wrong twice or fail the check by 5 or more, the door vents scalding steam in a 10-foot cone. DC 13 Dexterity saving throw, taking 2d6 fire damage on a failed save, or half as much on a successful one.

Act 3: The Assembly Line

Inside, the workshop is a chaotic mess of blueprints, scattered tools, and half-finished automatons. At the back of the room, Silas lies dead on the floor, a wrench clutched in his cold hand. Towering over him is his masterpiece gone wrong.

"A hulking automaton made of polished bronze and steel turns toward you. Its chest cavity glows with volatile blue arcane energy. Around it, two smaller, spider-like machines are busily welding scrap metal together, turning toward you with hostile clicks."

Boss Combat: The Clockwork King

1x Clockwork Overseer, 2x Mending Drones

Conclusion

With the Overseer destroyed, the arcane energy dissipates. The remaining machines in the village shut down. The party can safely loot Silas's body and workshop.

Treasure: A pouch with 50 GP, a Goggles of Night, and a unique magic item: The Clockwork Heart (Wondrous Item, requires attunement. As an Action, you can cast Mending. Once per dawn, you can use a Bonus Action to gain 1d8+2 temporary hit points).