"The game's up, Karl von Preussen," exclaimed Entwistle.
"Yes," admitted the spy breathlessly. "You've scored this time. I'd like to know how you traced me."
"You will in due course," replied Entwistle grimly, as he jerked his captive to his feet.
The next instant a cloud of pungent, burning powder struck Entwistle full in the face. The sudden, agonising pain as the grains filled his eyes took the Secret Service agent completely off his guard. Gasping for breath, and holding both hands to his face, he staggered blindly against the wall. Even in his physical torment he could hear von Preussen running swiftly.
In the moment of his triumph a craven trick had robbed Entwistle of his prey.
CHAPTER XXV
TRAPPED
Cold, grey dawn was stealing over the North Sea. Hull down to the east'ard, her cage-mast just showing above the horizon, lay the Hoorn Reefs Lightship. Off the tail of the bank that fringes Denmark's shores Hun submarines were in the habit of bringing up and receiving wireless orders before venturing through the inner mine-fields either to the mouth of the Elbe or northwards to the Baltic through the Kattegat.
Q 171 was moving slowly through the greyish-green water. Her triple torpedo-tubes were ready with their deadly complements; her quick-firers, trained fore and aft after the manner of U-boats returning to their bases, were ready for action at a moment's notice. The torpedo-men and gun crews, sheltering under the lee of the dummy conning-tower, were keenly on the alert, watching their commanding officer as he, in his turn, watched the broad expanse of sea over which the rising sun would shortly throw its slanting rays.