The light flickered up and down in long and short flashes. Still "Buzzer" Barling trilled away at the "Grand Reveille" nor raised his eyes from his work.

"O-K-E-W-O-O-D T-O B-A-R-L-I-N-G" he flashed.

He repeated the call twice and was spelling it out for the third time when Desmond saw the "Buzzer" raise his head.

"0-k-e-w-o-o-d t-o B-a-r-l-i-n-g" flickered the light.

The next moment the bedroom opposite was plunged in darkness. Immediately afterwards the light began to flash with bewildering rapidity. But Desmond recognized the call.

"I am ready to take your message," it said.

"S-t-r-a-n-g-w-i-s-e h-a-s g-o-t m-e ack-ack-ack," Desmond flashed back, "f-e-t-c-h h-e-l-p a-t o-n-c-e ack-ack-ack: d-o-n-t r-e-p-l-y; ack-ack-ack; s-e-n-d o-n-e d-o-t o-n-e d-a-s-h t-o s-h-o-w y-o-u u-n-d-e-r-s-t-a-n-d ack-ack-ack!"

For he was afraid lest the light flashing from the house opposite might attract the attention of the men downstairs.