The MYTHOS PACK: For the Greater Good is the third installment in The Circle Undone cycle for Arkham Horror: The Card Game. It introduces new narrative developments following The Wages of Sin, with unsettling events and disappearances in Arkham that require decisive actions from investigators. Players must navigate shifting alliances with the Order of the Silver Twilight, with choices affecting access to key locations and the Lodge's involvement in the story. The pack includes upgraded versions of player cards from The Secret Name, featuring revised single-class designs with new artwork and abilities tailored to each class. To use this expansion, players must own the Arkham Horror: The Card Game Core Set and The Circle Undone deluxe expansion.