“When a fellow looks over the field now,” said Bert as they walked to the hotel for supper, “he realizes just how valuable the Goliath is to Uncle Sam.”

“We’ve got the jump on them now,” said Andy. “Dubra failed in his attempt to damage the hangar and is now in our hands. That means the ‘inside man’ on whom Reikoff had counted for cooperation with this newcomer from Rubania is out of the picture and our guard lines have been tightened until it is almost physically impossible for anyone to get through. But even with all those precautions, we’ll continue to keep our eyes and ears open.”

Supper that night was a jolly affair, with introductions of Lieutenant Crummit and his companions to the engineers and foremen in charge of the building of the Goliath. The army flyers were keenly interested in the construction of the great dirigible and Andy enjoyed Lieutenant Crummit’s practical inquiries on the stability of the big gas bag, what it was expected to do when in the air and its availability for war-time use.

“We know in a general way,” he said, “but nothing very definite has appeared on the actual capability of the craft.”

Andy had an enthusiastic second in Bert and they went over a complete outline of the Goliath and its range, both in peace and war times, for the army men. By the time they were through, supper was over and the group broke up in twos and threes and straggled into the lobby of the old-fashioned hotel. The air was chilly and a great fire had been built in the fireplace. Lights were low and there was a general spirit of comradeship in the room. The radio had ceased its accustomed blare and a really excellent orchestra, devoid of the usual advertising propaganda, was playing familiar airs.

Someone started humming and in another minute the room was filled with lusty voices that took up the refrain. For half an hour they enjoyed the impromptu concert until a messenger boy came in with a telegram for Bert.

The young radio operator looked surprised as he fingered the yellow envelope, turning it over as though half expecting to find the address of the sender on the back.

“Now who under the sun could be telegraphing me?” he asked.

“Better open it and find out,” suggested Andy.

“A most original proposal,” replied Bert tartly. “It’s from Harry Curtis,” he cried as he read the message. “He’s going to the North pole as radio operator for Gilbert Mathews on the submarine Neptune.”