Strange disappearances haunt the city of Arkham, Massachusetts. With each object, building, or person that vanishes, they are erased not just from physical existence, but from history and memory as well. Only a select few investigators remember those that disappeared–or so they believe. Before long, the mystery unravels into an international conspiracy, and our wary investigators find themselves recruited by a shadowy government agency whose sole purpose is the collection and research of paradimensional implements they call “Keys.” However, they aren’t the only ones searching for them… In The Scarlet Keys Campaign Expansion, one to four investigators are sent on a dangerous assignment comprising up to ten scenarios all across the globe. Travel around a map of the world and chart your path to discover eldritch Keys before they are found by members of the mysterious and deadly Red Coterie…or work together with your foes to stop an even greater threat that lurks in the shadows. But can you really trust them? This expansion contains the entirety of The Scarlet Keys campaign. Players only need a copy of the Arkham Horror: The Card Game Revised Core Set to dive into the story.