“Right you are, Fischer,” was Lord Hastings’ smiling rejoinder, “though how you recognized me in all this German toggery is more than I can explain.”

The admiral advanced and wrung Lord Hastings’ hand.

“And why this German uniform?” he asked.  “And who is this young man with you?”

“I’ll answer the last question first,” smiled Lord Hastings, “by presenting to your excellency, my second officer, Mr. Frank Chadwick.”

Admiral Fischer acknowledged the introduction.

“Now for the answer to my other question,” he said.

In a few brief words Lord Hastings explained.  As he progressed with his recital Admiral Fischer became more and more astonished.  And when Lord Hastings had concluded, the admiral burst out: 

“And you mean to tell me the Germans have the temerity to attempt a raid in the very mouth of the Thames?”

Lord Hastings nodded.

“They certainly have,” he said quietly, and he produced the order he had received from the German admiral.

Admiral Fischer scanned it closely.

“It’s authentic enough,” he said finally, “I know his signature well.  And this raid is to take place at midnight, eh?”

“Well, no.  We are to gather at midnight.  How long it will take to reach the mouth of the Thames you can figure yourself.”

“I can,” declared the admiral.  “And I can also figure that if these submarines dare enter the Thames they will never get out.”

“But you must figure better than that, Admiral.  You must figure so they will be unable to do any damage.  That’s even better than figuring that they cannot escape after the damage is done.”

“So it is,” returned the admiral.  “Have you a plan?”

“Why, yes!  You must immediately order all warships and other craft now at the mouth of the Thames, further up river.  Order a swift torpedo boat flotilla down the river—­as many as are available—­and have half a dozen torpedo boats—­equipped with nets—­to take their places behind the motorboat fleet.”

“And then?”

“Well, the motorboats will attack the submarines as soon as they appear.  A few of them undoubtedly will be sunk.  Then let the rest retire.  The submarines, submerged by this time, will travel forward a bit.  At this point have the torpedo boats, with nets stretched, proceed down each side of the river.  Of course, the torpedo boats must advance at the moment the motorboats flee.”

“But I should think the Germans are too wary to be caught in a trap like that.”

“They won’t be, because they expect the raid to be too unexpected for such details to have been arranged.  Only one stipulation.  Instruct all your officers under no circumstances to fire at the first submersible to move up the river.”

“And why?” demanded the admiral.

“Chiefly,” smiled Lord Hastings, “because I don’t want to go to the bottom.”