The secrets of Wishtide

Mrs Laetitia Rodd is the impoverished widow of an Archdeacon, living modestly in Hampstead with her landlady Mrs Bentley.

She is also a private detective of the utmost discretion.

In winter 1850, her brother Frederick, a criminal barrister, introduces her to Sir James Calderstone, a wealthy and powerful industrialist who asks Mrs Rodd to investigate the background of an 'unsuitable' woman his son intends to marry - a match he is determined to prevent.

In the guise of governess, she travels to the family seat, Wishtide, deep in the frozen Lincolnshire countryside, where she soon discovers that the Calderstones have more to hide than most.