Emma and her father are always on the move, travelling from place to place as her father's work demands. Their new home, however, is different. There's a frightening woman who lives down the hall: she bears an uncanny resemblance to a witch. A mysterious light comes from her apartment, and a small boy seems to be trapped inside. School in this town is no happy place either, with an odd principal and a gang of girls who make tormenting Emma their special project. And strangest of all is the fact that there seem to be brownies - basement brownies, in the air vent in her bedroom. Haunted by visions of her mother, Emma travels through the brownie burrow to the valley of Hades to visit with the goddess Ceres, following a series of clues that lead her across the sea of memory to the centre of the world. There, on an inhospitable rock floating in a sea of steaming lava, Emma must find a way to release her mother from the sea of memory and restore magic to both the brownie burrow and the human world above.