Guy Maichment, a landscape gardener, pays a late-night visit to his aunt, Dame Claudia McRae, the well-known veteran archaeologist who lives in an isolated cottage near Helpston, and sees that her front door is wide open.
When he enters the house he discovers that his aunt has vanished, leaving no clue of what has happened to her except a broad smear of blood on her hall wall.
The Spalding Archaeological Society is holding its annual conference at the Welland Manor Hotel nearby.
Alex Tarrant, its attractive Secretary, is about to embark upon an affair with Edmund Baker, the County Archaeologist.
Edmund and Oliver Sparham, the County Heritage Officer, were both Claudia's proteges in their youth.
Oliver visits her on the day of her disappearance, making him the last known person to see her alive.
Detective Inspector Tim Yates is detailed by his boss to investigate, even though Helpston is outside the area normally served by South Lincolnshire police.
He is frustrated at therefore being excluded from the pursuit of an organised drugs syndicate which employs young children as couriers.
Detective Constable Juliet Armstrong delves into Dame Claudia's past, and discovers that some of her celebrated theories derive from questionable political opinions forged during the Second World War.
Meanwhile Tom Tarrant, Alex's social worker husband, tries to help two terrified young brothers who have been recruited by the drugs gang.
DI Yates himself has personal problems: his normally cheerful and supportive wife, Katrin, is desperately unhappy, but won't tell him why.