The destroyer staggered for a moment, and the entire central section
of the ill-fated ship disappeared. The bow and stern came together
with a rush and went down in a swirling maelstrom of water. The plane
lurched in the air as a thundering crash rose from the sea.

The second destroyer, in no way daunted by the fate of her colleague,
rushed to the attack. Dr. Bird pounded his key frantically in an
attempt to turn her back. His message was too late or was
misunderstood. Straight over the submarine went the second ship. Again
came the red flash. The forward half of the destroyer disappeared and
the stern slid down into a huge hole which had opened in the water.

"He's invulnerable!" cried the doctor. He pounded his key with
feverish rapidity. The two remaining destroyers slackened speed and
veered off. Slowly, as though loath to turn their backs on the enemy,
they headed out for the broad Atlantic and comparative safety.

The submarine went slowly on her way. She did not turn west at the
mouth of the Potomac but continued on up the bay. As long as there was
light enough, the doctor's plane kept above her but the fading light
soon made it impossible to see her. When she had disappeared from
view, the doctor reluctantly gave the word to return to Washington.

* * * * *

"Where do you suppose he will attack next, Doctor?" asked Carnes when
they sat again in the doctor's private laboratory.

"Washington, of course," said Dr. Bird absently as he looked up from a
pile of telegrams he was running through.

"Why Washington?"

"Use your head. Representatives of every civilized power are in
Washington now at the President's invitation to consider means of
halting the anti-religious activities of the Soviets. The destruction
of the city and the killing of these men would be a telling blow for
Russia to strike."

"But, Doctor, you don't think--"

"Excuse me, Carnes; that will keep. Let me read these telegrams."

For half an hour silence reigned in the laboratory. Dr. Bird laid down
the last message with a sigh.

"Carnes," he said, "I'm check-mated. I sent out a hundred
ultra-sensitive short wave receivers yesterday. Four of them were
located within fifty miles of Wilmington, North Carolina. One of these
four was destroyed, but none of the others detected a sign of a wave
during the attack. One of them was within a hundred feet of the edge
of the hole. If he isn't using a ray of some sort,