When a young woman dies in a busy park in broad daylight, McDonald and Dodds are called in to untangle the mysterious circumstances of her death. Who is she? How did she die surrounded by witnesses? And how is it possible that she is smiling? All roads seem to lead to Professor George Gillan (Alan Davies), a linguistic anthropologist who lives in a rambling mansion with his eccentric mother, Agnes (Sian Phillips), whose 100th birthday is days away. DS Dodds is sure that the house has something to do with the murder, but in uncovering Belvedere’s history, Dodds also unearths secrets in his own past.