From the streets of Paris to the city's subterranean catacombs, your pursuit of the truth behind The King in Yellow leads you farther and farther from Arkham's familiar landmarks. But the streets, the language, and the eerie, dark tunnels aren't the only foreign elements at play. There's something distinctly otherworldly in the Parisian catacombs…
In The Pallid Mask scenario, you and your fellow investigators will enter these tunnels in search of a stranger whom you believe must be connected to the events surrounding the performance of The King in Yellow at the Ward Theatre in Arkham. But with each new strange twist and turn, you'll find yourselves only stepping deeper into mystery. Perhaps you can follow the tunnels all the way to the pulsing heart of the play's mysteries, but there's a chance, too, you'll simply find yourselves lost amid the shifting landscape. What begins as a trek through moist and clammy tunnels of stone may become a journey that leads you under the earth, through The Gate to Hell, and straight to your demise at the Well of Souls or some other forgotten chamber.
Destined to be a fan-favorite, the scenario from The Pallid Mask utilizes the game's locations in a novel way, bringing them into play only as you travel through them, and arranging them in a constantly shifting and unpredictable fashion. Each new step through these labyrinths could be your last.
—description from the publisher