Voxai Colony Alpha (ヴォクサーコロニー・アルファ Vu~okusākoronī arufa?), also shortened as Colony Alpha, is the twelfth area that appears in Sonic Chronicles: The Dark Brotherhood, the fifth area encountered in the Twilight Cage and as well the penultimate stage of the game. It is one of two Voxai homeworlds, located in Sector Charybdis of the Twilight Cage. This is where the Overmind are fought.