“All Frogs listen. Mills is dead. Number Seven finished him this morning. Number Seven receives a bonus of a hundred pounds.”

The voice was clear and singularly sweet. It was a woman’s.

“Twenty-third district will arrange to receive Number Seven’s instructions at the usual place.”

Dick’s heart was beating thunderously. He recognized the speaker, knew the soft cadences, the gentle intonations.

There could be no doubt at all: it was Ella Bennett’s voice! Dick felt a sudden sensation of sickness, but, looking across the table and seeing Elk’s eyes fixed upon him, he made an effort to control his emotions.

“There doesn’t seem to be any more coming through,” said the operator after a few minutes’ wait.

Dick took off the headpiece and rose.

“We must wait for the direction signals to come through,” he said as steadily as he could.

Presently they began to arrive, and were worked out by a naval officer on a large scale map.

“The broadcasting station is in London,” he said. “All the lines meet somewhere in the West End, I should imagine; possibly in the very heart of town. Did you find any difficulty in picking up the Frog call?” he asked the operator.