And all these speculations failed to throw the faintest light on the main question: “Who was this woman?”

A couple of days passed, during which Thorndyke made no further reference to the case. He was, most of the time, away from home, though how he was engaged I had no idea. What was rather more unusual was that Polton seemed to have deserted the laboratory and taken to outdoor pursuits. I assumed that he had seized the opportunity of leaving me in charge, and I dimly surmised that he was acting as Thorndyke’s private inquiry agent, as he seemed to have done in the case of Samuel Wilkins.

On the evening of the second day Thorndyke came home in obviously good spirits, and his first proceedings aroused my expectant curiosity. He went to a cupboard and brought forth a box of Trichinopoly cheroots. Now the Trichinopoly cheroot was Thorndyke’s one dissipation, to be enjoyed only on rare and specially festive occasions; which, in practice, meant those occasions on which he had scored some important point or solved some unusually tough problem. Wherefore I watched him with lively interest.