Ballybeg is a small village, on the western coast of Ireland, where usually nothing happens. Life flows calmly and monotonously around the parish church of Father Reginald McKenzie, the village Pub and the Minimarket, which belongs to William Collins, a handsome and enigmatic man who has come back to his birthplace after 20 years.
Not far from the village there is the well-known and exclusive St. Osmanna's College for young ladies, run by Mother Mary McNally, the determinate and energetic Mother Superior.
Along the coast road, by the panoramic point overlooking the cliff, the Fitzpatricks' manor is the old and solitary Julia Fitzpatrick's home. The elderly Mrs Fitzpatrick, her step-son, the local police station chief, Peter Boyle, William Collins and Father Reginald are an apparently incongruous small group of very close friends who one day found themselves involved in a dramatic series of events which upset the sleepy routine of the village. A murderer has started killing nuns, without any apparent motive.
Other disquieting presences appear in the village. Who are they and what are they looking for?
William, Peter, Julia and Reginald will solve their first case following scattered clues and using their deductive intelligence.
Nothing will be the same anymore in Ballybeg, after the solution of these mysteries.