The wealthy financier, John William Stone, is found dead beneath the window of his home, having fallen, jumped, or been pushed. The will charges his widow, Elizabeth Lady Ravenscliff, with finding Stone’s lost child. She had known nothing about this episode in his life, but she is determined to honour his wish.

The story centers on a financial mystery told in three parts that move further back in time: London 1909, Paris 1890, and Venice 1867. Each story gives a different version of Elizabeth – none refutes any of the others.

In the first part, Elizabeth is cool, superior and in charge, but her grief is genuine. She hires Matthew Braddock to look for the missing child, suggesting that he pose as a hired biographer. The writer is smitten with Elizabeth and concludes that there was no lost child.

The second part is narrated by a spy, Henry Cort. In this version, Elizabeth began as a waif who became a high-class prostitute, involved in affairs of state. Addicted to drugs, she was dangerous and selfish, but Cort never realizes that she is his sister.

The last (but earliest) part is told by Stone himself about an affair he once had in Venice and its sorry end. The last few pages draw the disparate threads together and account cleverly for all the mysteries.