But there was once when it seemed that all—­Lord Hastings, Frank and Jack—­had come to their end.  It came about in this wise:  After a long cruise, which resulted in great successes, their submarine, D-16, had come to grief in the Dardanelles.  They were caught below and it seemed that all must perish.

Then Jack had decided that it was futile for all to die; there was safety for all but one.  A deck of cards decided who was to stay, and Jack had drawn the fatal card—­the ace of spades.

Officers and crew were launched to safety by means of a torpedo tube; and Jack sat down to await the end.  But, in some unaccountable manner, the submarine had suddenly risen to the surface, and Jack, taking advantage of the single instant the vessel was above water before it took its final death plunge, flung himself clear.  And thus all were saved.

But, because of their desperate experiences, they were unfit to immediately resume new duties; so all had returned to England until such time as they would be physically in shape again.

Now Jack Templeton, although young in years, was wise in the ways of the world.  Also he was of huge stature and as strong as an ox, as he had proved more than once when put to the test.  Frank, although by no means as large as his chum, was sturdy and strong, and able to give a good account of himself when occasion required.

The one noticeable difference between the two was that Frank was high-tempered and quick, whereas Jack was always cool and collected.  And this very fact had more than once showed that Jack, while not exactly more dependable, could always be relied upon to keep his head.

While both were skillful in the use of weapons, here was a place where Frank excelled.  He was a dead shot with rifle or revolver and was a strong swordsman.  Jack was a good shot himself and a skillful fencer, but he was not in Frank’s class when it came to the use of sword or firearms.

Upon their last expedition Jack and Frank had acted as first and second officers respectively of the submarine, and both now held the rank of first lieutenant.  Their promotions had come deservedly.  They had the implicit confidence of Lord Hastings and more than once had offered valuable advice, which Lord Hastings had acted upon.

Now a few words about the progress of the war.  The seven seas had for some time, save for the presence of the German submarines, been swept clear of German, Austrian and Turkish fighting ships.  Not a one remained at large to prey upon the shipping of the Allies.  The real fighting strength of the navies of the three central powers still remained in their own fortified bases, well guarded by mines.

The Allies had established such an effective blockade that none dared to venture forth.  So the naval situation was practically at a standstill, where indications pointed to its remaining until the main German fleet, bottled up in Heligoland, and the main Austrian fleet in the Adriatic should summon sufficient courage to sally forth and give battle; and there had been nothing to indicate any sudden action on the part of either.