preceding each crime; and both sets had been made after the snow had stopped falling when they would be distinctly visible and determinable. This was not a particularly striking coincidence, but it was sufficiently arresting to create a slight strain on my cortex cerebri. And the strain increased perceptibly this morning when Snitkin reported his discovery of fresh footprints on the balcony steps; for once again the same meteorological conditions had accompanied our culprit's passion for leaving spoors. I was therefore driven to the irresistible inference, as you learned Solons put it, that the murderer, so careful and calculating about everything else, had deliberately made all these footprints for our special edification. In each instance, d' ye see, he had chosen the only hour of the day when his tracks would not be obliterated by falling snow or confused with other tracks. . . . Are you there?"
"Go ahead," said Markham. "I'm listening."
"To proceed, then. Another coincidence attached to these three sets of footprints. It was impossible, because of the dry, flaky nature of the snow, to determine whether the first set had originated in the house and returned there, or had first approached the house from the street and then retreated. Again, on the night of Chester's demise, when the snow was damp and susceptible to clear impressions, the same doubt arose. The tracks to and from the house were on opposite sides of the front walk: not a single footstep overlapped! Accidental? Perhaps. But not wholly reasonable. A person walking to and from a door along a comparatively narrow pathway would almost certainly have doubled on some of his
