Twice my friend Stieber called in the days that followed, but I flattered myself that from me he learnt nothing.

On the morning of New Year's day five letters were pushed through the box. Eagerly I tore them open. The last, bearing a Dutch stamp, with the postmark of Utrecht, contained the expected card, with the inscription "To dear Heinrich," a small hand-painted scene upon celluloid, with forget-me-nots woven round the words "With the Compliments of the Season."

Half an hour later, having burned the card according to my instructions, I despatched the mysterious message to Manchester.

That evening, about ten o'clock, Stieber called for me to go for a stroll and drink a New Year health. But as we turned from Clarges Street into Piccadilly I could have sworn that a man we passed in the darkness was old Van Nierop. I made no remark, however, because I did not wish to draw my companion's attention to the shuffling old fellow.

Had the telegram, I wondered, brought him to London?

Ten minutes later, in the Café Monico, my friend Karl lifted his glass to me, saying:

"Well, a Happy New Year, my dear friend. Take my advice, and don't trust your Baron too implicitly."

"What do you mean?" I asked. "You always speak in enigmas!"

But he laughed, and would say no more.

Next day dawned. Grey and muddy, it was rendered more dismal by my loneliness. I idled away the morning, anxious to be travelling again, but at noon there was a caller, a thin, pale-faced girl of fifteen or so, poorly dressed and evidently of the working-class.