“Well, we never lose an opportunity to do our duty, be the enemy large or small fry,” observed McClure.

After waiting for a few moments longer, and being advised of the continued steady approach of the ship, the young lieutenant decided to move in closer to get within better range, and then rise to the surface and “look her over.”  It was well on toward four o’clock and soon would be daylight.

Creeping along at half speed, the Dewey veered slightly to starboard and steered a course N.N.W. toward the oncoming craft.  After cruising thus for a quarter of an hour the submarine was stopped altogether again and her captain conferred again with his wireless chief.

“She seems to have changed her course,” announced Smith after listening intently at both port and starboard microphones.  “As near as I can calculate she has turned off abruptly to port and is running due east toward the coast.”

“Fine!” exclaimed McClure.  “A German for sure.  And now perhaps we can track her to her lair.”

In a few moments the Dewey thrust her periscopes up out of the sea and set out in pursuit of the unknown ship.  It was yet too dark to make her out, except for a dim blur that showed faintly against the background of the Belgian coast.  By striking the Dewey’s latitude and longitude they figured they were at a point five or six miles off Blankenberghe.

“Where do you suppose she is heading for?” asked Cleary.  He was plainly puzzled.

“There probably is a canal near at hand that the Germans have dug out since their occupation of Belgium, and which they now are using as a retreat for their light draft vessels—–­possibly a submarine base,” answered McClure.

For a time the Dewey followed steadily on in the wake of the German.  It was not long until McClure, at the forward periscope, was able to get a better look at the foe.

“A big destroyer,” he announced.  “I can make out her four funnels.”

It was now apparent to the lieutenant that they were approaching close to the coast and that very shortly the destroyer must turn again to the sea or else take her way into some tortuous channel leading inland.

“Reckon we have gone as far as we can,” he declared after a further observation.  He had in mind the fact that the approach to the waterway for which the destroyer was headed most certainly was mined and that without a chart of the course he was running the risk of driving into one of the dangerous buoys.

He determined to chance a shot at the destroyer, submerge and go out to sea again.  Sighting on the dimly outlined destroyer he released a torpedo and then, without waiting to observe the result of the random shot, gave the signal to dive.

Down went the Dewey.  And in another moment, as the gallant sub slipped away into the depths, she lurched suddenly with a staggering motion and brought up sharp with an impact that shook the vessel from stem to stern.  Officer Cleary was catapulted off his feet and crashed into the steel conning tower wall, with an exclamation of pain.  The Dewey seemed to have run hard against an undersea wall.