The "Mutant Chronicles: Siege of the Citadel BROTHERHOOD Expansion" by Modiphius is a board game expansion released in 2021. The game offers a single player experience with a horror and monster theme, suitable for players aged 12 and up. As part of the Mutant Chronicles series, players can delve into the dark and twisted world of the game, adding new elements and strategies to enhance their gameplay experience. Made in China, this expansion adds depth and excitement to the original game, making it a must-have for fans of the franchise.