A funny, fast-paced paranormal adventure for children. Jessie Minahan and her mother stumble across the Dublin Button Factory in the grounds of the old mill. The factory is a front for a detective agency, and hiding in the walls of the old building are ghosts - crotchety Greenwood and the younger, mischievous G. Together, ghosts and humans discover a secret power at the heart of the mill - a dangerous vortex whose imminent opening could spell disaster for the inhabitants of Dublin.