What renders this conjecture entirely probable is that the buttoned-up man, on catching sight from the shore of a hackney-coach on the quay as it was passing along empty, made a sign to the driver; the driver understood, evidently recognized the person with whom he had to deal, turned about and began to follow the two men at the top of the quay, at a foot-pace. This was not observed by the slouching and tattered personage who was in advance.

The hackney-coach rolled along the trees of the Champs-Élysées. The bust of the driver, whip in hand, could be seen moving along above the parapet.

One of the secret instructions of the police authorities to their agents contains this article: “Always have on hand a hackney-coach, in case of emergency.”