 The book's ending leaves ambiguous whether Doyle and Eileen resume their affair, begun in "The List of Seven".At this time, Doyle's wife, Louisa, was suffering the debilitating effects of tuberculosis, which prevented them from being physically close.In real life, after Louisa's death, Doyle remarried to a woman, Jean Leckie, with whom he had fallen in love while Louisa was still alive, though he kept their relationship platonic out of loyalty to Louisa.