The woman Petre had sent a letter to Digby Kemsley to the Poste Restante in Brussels under the name of Bryant. If this were so, the fugitive must be in the habit of calling for his letters, and it was the great black façade of the chief post-office in Brussels that I was watching.

The business-day was just drawing to a close, the streets were thronged, the traffic rattled noisily over the uneven granite paving of the big square. Opposite the Post Office the arc lamps were shedding a bright light outside the theatre, while all the shops around were a blaze of light, while on every side the streets were agog with life.

Up and down the broad flight of steps which led to the entrance of the Post Office hundreds of people ascended and descended, passing and re-passing the four swing-doors which gave entrance to the huge hall with its dozens of departments ranged around and its partitioned desks for writing.

The mails from France and England were just in, and dozens of men came with their keys to obtain their correspondence from the range of private boxes, and as I watched, the whole bustle of business life passed before me.

I was keeping a sharp eye upon all who passed up and down that long flight of granite steps, but at that hour of the evening, and in that crowd, it was no easy matter.

Would I be successful? That was the one thought which filled my mind.

As I stood there, my eager gaze upon that endless stream of people, I felt wearied and fagged. The Channel crossing had been a bad one, as it so often is in January, and I had not yet recovered from my weird experience at Colchester. The heavy overcoat I wore was, I found, not proof against the cutting east wind which swept around the corner from the Boulevard Auspach, hence I was compelled to change my position and seek shelter in a doorway opposite the point where I expected the man I sought would enter.

I had already surveyed the interior and presented the card of a friend to an official at the Poste Restante, though I knew there was no letter for him. I uttered some words of politeness to the man in order to make his acquaintance, as he might, perhaps, be of use to me ere my quest was at an end.

At the Poste Restante were two windows, one distributing correspondence for people whose surname began with the letters A to L, and the other from M to Z.

It was at the first window I inquired, the clerk there being a pleasant, fair-haired, middle-aged man in a holland coat as worn by postal employees. I longed to ask him if he had any letters for the name of Bryant, or if any Englishman of that name had called, but I dared not do so. He would, no doubt, snub me and tell me to mind my own business.