"Manchester 1809. When budding young criminal Mary Jebb swindles Michael Croxton's brother with a blank pound note, he chases her into the night and sets in motion a train of sinister events. Condemned to seven years of transportation to Australia, Mary sends him a 'Penny Heart'-a token of her vow of revenge. Two years later, Michael marries naive young Grace Moore. Although initially overjoyed at the union, Grace quickly realizes that her husband...

In 1925, the Honourable Daisy Dalrymple Fletcher, her husband, Alec Fletcher (a Scotland Yard Detective) and their new twin infant children inherit and move to a new, larger house on the outskirts of London proper, in a stage of slight disrepair (thanks to an aged, now deceased, uncle). Set in a small circle of houses and a communal garden, it seems a near idyllic setting. That is until a dead body turns up half-hidden under the bushes of the communal...