CHAPTER XXI
CHECKMATE
The "Nordby" was an hour after her scheduled time in casting off from the quay. Slowly she threaded the tortuous channel until clear of the dangerous sandbanks off the Danish coast. Here the pilot, with ill-concealed relief, handed over the wheel, bade the skipper farewell, and took to the boat that was being towed alongside. Thanking his lucky stars that his duty did not require him to navigate the vessel through the mine-strewn, submarine-infested North Sea, he rowed back to Esbjerg, while the "Nordby," increasing speed, shaped a south-westerly course.
Keeping Otto Oberfurst well under observation, although they took care to render themselves as inconspicuous as possible, Tressidar and Fuller remained on the qui vive.
Their compatriot, meanwhile, paced the deck betwixt the mainmast and the taffrail, maintaining a well-assumed indifference to his surroundings. He was aware that the spy had already made himself acquainted with the fact that an interned British officer on parole was amongst the passengers, and Oberfurst was likely to be keeping a stealthy watch on him. So from the moment he had seen the spy board the ship Holloway had kept aloof from Tressidar and his chum.
The "Nordby" was well beyond the three-mile limit when the look-out reported a submarine on the starboard bow. Instantly there was a rush on the part of the passengers and crew to see the strange under-water craft. Speculation ran high as to her nationality and whether she would attempt to destroy the neutral vessel with the ruthlessness peculiar to the Huns.
"She's one of our 'S' class," declared Tressidar to his chum. "That's all right. Now for friend Oberfurst."
The spy was no longer on deck. Down the companion ladder the two British officers hastened and cautiously took up a position just outside the German's cabin. They could hear him fumbling with the locks of his portmanteau.
Then the door was opened, and Oberfurst appeared, with a small leather wallet resembling a camera case slung from his shoulder with a strap.
"Hands up!" ordered Tressidar sternly, the muzzle of his revolver, held by a steady hand, within a foot of the spy's head.