The Mother of the Fog is a sacred spirit worshipped by members of the Children of Atom, who they believe to be a saint of their god, Atom. The player finds her when they drink irradiated water from Atom's Spring on The Island during the quest Visions in the Fog. She is a dark, ghostly figure, shrouded in black smoke. She leads the player to an abandoned building in the middle of the fog. It is here that they will find the "Mother icon", a small statue. It is also indicated she is not supernatural, as there are several notes on the top floor of a wrecked house near Haddock Cove seemingly written by the Mother herself.