The snow was falling heavily as we turned into Park Lane.

“All in all,” remarked Holmes in a gay tone, “it has been a very satisfactory night’s work. We have recovered the Army ciphers and unmasked a singularly dangerous traitor.”

I nodded. “And now Princess Zelda will travel on to Venice and meet the foreign agents there, only to discover that she has brought them nothing but a wad of blank paper!”

“Not quite blank,” returned my friend. “I took the liberty, before resealing the envelope, of inscribing upon the top sheet a little message for Zelda and her colleagues which reads, ‘The Compliments of the Season, from all your friends in England!’”