This book tells the remarkable story of the connection between the ghostly apparition of Susan Leakey in Somerset in the 1630s and the only (‘to date’) execution for sodomy of an Anglican bishop, John Atherton of Waterford, in 1640. Peter Marshall gives us, though, a detective story rather than a ghost story, skilfully piecing together a complicated history from both sides of the Irish Sea, placing it adroitly in the complex context of the Laudian ascendancy over the ‘British Church’, and providing a considerable examination of the ‘afterlife’ of Mother Leakey's ghost and the Atherton scandal from the coffee houses of Georgian London to the fiction of Sir Walter Scott. The book is also an extended essay on the nature of the historian's vocation, making what I take to be an implicit point (and, I assume, a somewhat playful one) that as ghosts transgress the boundaries between the worlds of the living and the dead, so the historian occupies, and even ‘transgresses’, the border country between imagination and evidence. The informal style of Marshall's book indicates that Mother Leakey is intended for a general readership and its conversational authorial voice may rub some professional historians the wrong way. For the specialist, however, there is insight provided about the Anglican episcopate in Ireland and Laud's relationship to it. Mother Leakey also presents a fresh look at that old bone of contention of how far the boundaries between popular and elite culture were redrawn by the Reformation – and how far those new boundaries were themselves ‘transgressed’.