When postman, David Christie, finds a strangely carved box in his garden, he does not realise that his life is about to change. First the enigmatic Professor Jorunn Nechtan offers to buy the box, and then helps him lose his job. Gradually David is drawn into a web of intrigue that spans the centuries from prehistory to the present day, in which his wife, Catriona, plays a prominent role. Set in a Dundee where nothing is quite what it seems, Mother Law illuminates many periods of the city's historical past through David's eyes. He meets Bronwen, one of the mysterious People of Peace who claim to be the original inhabitants of the land, and relives a previous life when General Monck's army destroys the city in 1651. With Bronwen fighting Jorunn for his support, David starts a new career as a boat operator, and steers a middle course over the Tay to find a missing manuscript that will restore balance to the world.