y to the north of Scotland, a member of a tour group reluctantly led by a young minister is found dead in a Neolithic tomb. The police suspect the death to be the work of a serial killer who has murdered two clergymen on the same date-the summer solstice-in the last two years. The Rev. Seth Ludington and his sharp-tongued sidekick, Harriet van der Berg, agree at first, but come to suspect otherwise and find themselves pulled into another investigation, leading them into danger and the darkest moral terrain.