from here to Paddington in about fifty seconds."

The morning journey to Devonshire was a dispiriting one despite
the fineness of the day. T. X. had an uncomfortable sense that
something distressing had happened. The run across the moor in
the fresh spring air revived him a little.

As they spun down to the valley of the Dart, Mansus touched his
arm.

"Look at that," he said, and pointed to the blue heavens where, a
mile above their heads, a white-winged aeroplane, looking no
larger than a very distant dragon fly, shimmered in the sunlight.

"By Jove!" said T. X. "What an excellent way for a man to escape!"

"It's about the only way," said Mansus.

The significance of the aeroplane was borne in upon T. X. a few
minutes later when he was held up by an armed guard. A glance at
his card was enough to pass him.

"What is the matter?" he asked.

"A prisoner has escaped," said the sentry.

"Escaped - by aeroplane?" asked T. X.

"I don't know anything about aeroplanes, sir. All I know is that
one of the working party got away."