A man with his coat collar turned up ran through the driving rain and entered the shed. It was Ferret.
"Something's gone wrong," he declared. "I've just had a telephone message from my colleague. I'm off to the post-office. If you want me during the next ten minutes you'll find me there."
Hawke had at length managed to get a word with his former fellow-traveller, who happened to be a staff-officer of the Eastern command. The detective had been under a misapprehension. The officer had good reason for ordering his arrest; but the comedy threatened to take a serious development. Even when the detective showed his credentials the officer was not satisfied. He proposed telegraphing to Scotland Yard, but Hawke, mindful of a former failure, induced him not to do so. The detective, who had occasion to contrast unfavourably the summary powers of arrest under the Defence of the Realm Act with those allowed by the Civil Power, was eventually allowed to communicate with his brother officer at Parkeston Quay. And then the military authorities required a considerable amount of convincing. It looked as if Detective-inspector Hawke would have to remain under arrest until next morning.
While Ferret was losing time and patience in his efforts to release his confrère, Ross and Vernon noticed a man hurrying along the quay. He was short and thick-set. He wore a long mackintosh, the collar of which was turned up and helped, with the peak of his cap, to hide his features.
Suddenly the man's foot tripped over a ring-bolt. He cursed under his breath, but sufficiently loudly for the lads to overhear.
Ross gripped his companion's arm. The fellow was swearing in German.
"Von Ruhle!" he whispered. He made a movement as if to issue from his place of concealment, but Haye restrained him.
"Hold on!" he cautioned in a low voice.
The man paused on the gangway. A partly shaded electric light threw a glare upon his face. He wore a heavy beard and moustache.
"You're wrong," whispered Vernon.