Seligmann heaved himself upward with a mighty effort; but the revolver muzzle was pressed yet more forcefully against his skull, and the constable's knees were almost breaking his back.
The footsteps approached swiftly, and at length the flash of an electric torch shed its slanting ray upon the desperately struggling pair.
"What's up? Hullo, Challis, I've been searching for you."
It was the voice of Mark Redisham. He had received a telephone message from the police-station, bidding him find Constable Challis and help him to waylay this same suspected motor-car, coming from Buremouth.
"Quick! Feel in my back pocket for the handcuffs," Challis ordered, dropping the revolver and seizing his prisoner's two wrists. "Right. Now hold his head while I put 'em on. Then you can drive him and me to the police-station."
There was a sharp clip as the steel rings were locked upon the German's wrists. Mark went to the car, turned up the lights, and got ready. They bundled the prisoner into the body of the car, where Challis sat with him, covering him with the revolver. Mark drove off through the town, and soon brought up at his destination. In the car they discovered a complete wireless outfit, a signalling lamp, and a handbag containing certain compromising documents.
"Yes," said the Superintendent, when Seligmann was safely locked in a cell. "He has been busy with that wireless apparatus to-night. Some of his messages were jammed, but not all of them. Not all."
CHAPTER XXI.
THE RAIDERS.
Whether Seligmann's wireless messages had anything to do with the matter or not can only be conjectured. But it is true that at earliest dawn on that same misty, November morning the fishermen of the Haddisport herring fleet, at work with their drift nets south of the Dogger Bank, were surprised by the sudden appearance in their midst of a squadron of eight grey-hulled Dreadnoughts and cruisers, bearing due westward at breakneck speed.