“We must go back to London,” said Sir John at last. “I will wire Sir Christopher Somerville—he’s President of the Geographical Research Society you know—and Professor Chard of the Geological Society to meet us in town. I will put the whole matter before them and take their advice. But, my dear boys, I can scarcely yet realize I have you back with me again.”

“Have you done any more with your Argenta?” asked Desmond suddenly.

Sir John’s eyes shone. “Come with me,” said he and he took them to the hangar. “She is complete and I think perfect,” said he simply. Very beautiful indeed looked the Argenta. There was a perfect grassy incline leading from the hangar to a large, flat field.

“I shall run her down the slope,” he explained, “and the field in the hollow is splendid for both ascending and descending.”

“Have you tried her yet?”

“No. We were going to try her yesterday, Mr. Alan,” said Masters, “but Sir John postponed it until your arrival.”

“And we must postpone it again, I am afraid,” said Sir John, rather sadly.

“Is it necessary, Uncle John?” asked Mavis.

“I think so, my dear. Your story is too wonderful to keep back a moment longer than is necessary. We will go to London to-morrow, and after all formalities are done with, will come back, try the Argenta, and if she is as I think she is, we will go for a long holiday in her.”

“Shall I accompany you?” asked Masters.