"Haven't you got any clue to their identity, sir?" asked the inspector, who remained at his side.
"None; it happened during my absence. They tied up my friend and gagged him. I came across country in my flying machine yonder."
"They'll lose this boat for certain," said the inspector, as the steamer's warning siren sounded. "You're sure they are Frenchmen?"
"Yes; well, they left a French newspaper behind them."
"Do you happen to have it with you?"
Burton drew the crushed paper from his pocket, and handed it to the policeman, who unfolded it, and displayed a torn sheet, with only the letters IND remaining of the title.
"That's the Indépendance Belge," said the inspector at once. "I expect they're Belgians, and aren't coming here at all. Ostend's their mark, I wouldn't mind betting."
"Via Dover, of course. Is there a boat?"
"One at 4.30, sir. I'm afraid they've dished you."
"I'm not so sure about that," said Burton, glancing at his watch. "It's now 4.20; this boat's off. If the Ostend boat is ten minutes late too I can get to Dover in good time to have it searched."