With the petulant words Billy tore the note to shreds and cast them to the wind.

“Between the Cossack and this alleged silversmith,” complained Henri, “we will have more than enough practice as artful dodgers.”

“Got us both going and coming,” gloomily added Billy, “and no show for argument.”

“We don’t have to respond to that message, anyhow.”

“I don’t know about that, Henri; we might be able to convince the crank at the shop that we haven’t any hold on underground wires, and so get rid of him.”

“And then prove an alibi when we meet that Cossack.”

Henri wore a grin as he put this extra spoke in the wheel of hope that his chum was turning.

Humor, however, was not catching to Billy this evening. The boys sat in silence at the mess table, and as silently stole away to bed.

The young aviators had no call for their services the next day, and Billy insisted that they play a quitting visit to the little shop in the square. Besides, he had urged, they were less likely to encounter the Cossack out in the big city than if they idled about headquarters. His motion prevailed, and shortly before the tower clocks sounded the twelve strokes, the chums were rounding the tall column and nearing the symbol of the silversmith.

Ricker had an assistant on duty in front this day, a wild-eyed individual literally overgrown with hair on head and face. When the boys entered the shop the queer-looking clerk spoke not a word, but simply pounded with his knuckles on the counter.