John Rawlings has returned to his beloved London after spending time in America where revolutionary trouble is dangerously brewing. Having made a substantial sum selling carbonated water, Rawlings buys a country house situated on the banks of the Thames in Strand-on-the-Green in Chiswick. But one morning a small child falls into the river, and John, witnessing her rescue, hears her say she did not fall but was pushed. Not long after he is at the theatre with his daughter Rose when a woman is lowered by her ankles from the Slips... As he goes to her aid John Rawlings gets the feeling that some deadly mystery is about to unfold. Could the two incidents possibly be connected?