April 1967. As spring blooms, the death of artist Simon Hallward in a horrendous house-fire leaves Oxford City Police baffled as to the cause of the blaze. When a young housewife dies, seemingly of the same mysterious ’tummy bug’ that has seen half of Chief Superintendent Bright’s men go on Sick Leave, DC Endeavour Morse’s investigation leads him to an inner-city supermarket, Richardson’s, owned by a wealthy family of the same name, descended from a line of Quakers.