inclination to remain in harbour," rejoined Fox. "When
there's a chance, you can bet your bottom dollar that our fellows seize
it. Quite recently one of our submarines found herself alone and
disabled in the Bight of Heligoland. Undismayed, her
lieutenant-commander signalled to a passing German trawler, covered her
with his guns, and made the Hun tow the crippled submarine into British
waters. Then he released his involuntary benefactor, but before so
doing can you guess what he did?"

"No," replied both lads.

"Made the Huns line up on deck and sing the 'Hymn of Hate'. You can
imagine the surprise of the trawler's men, who, judging by the
treatment meted out to our fishermen by the German submarines, expected
nothing less than imprisonment and the loss of their boat. But it's
close on one bell," remarked Fox at length. "You're messing with the
skipper to-day, I believe. He's quite a decent sort when you know him
properly, but it takes a bit of doing."

A seaman strode up to the bell and gave it a sharp stroke. Just then a
messenger hurried from the diminutive "wireless" room abaft the
chart-house and, leaping down the ladder at a single bound, knocked at
the door of the Captain's cabin.

"Stow those things away, Sparkes," exclaimed Captain Syllenger. "Lunch
will have to wait."

He dashed out of his cabin. On the way to the bridge he passed Fox and
the two midshipmen.

"You'll have to tighten your belts, my lads," he announced. "We've
just had a message through. A strafed unterseeboot has been spotted
trying to get into Spithead. If we don't nab her within half an hour,
I'll eat my hat!"

CHAPTER XVII

A Double Bag

It was a sea-plane, flying at fifteen hundred feet above the Warner and
The Nab Lightships, that had detected an elongated shadow creeping
stealthily over the shingly bottom close to the Dean Tail Buoy. The
shadow was that of a German unterseeboot, since none of the British
submarines were known to be in the eastern approaches to Spithead.
Evidently she had gone out of her course, for instead of being in the
main channel she was well to the north of it. More than likely the
strong east-going tide, which hereabout surges at such a rate that it
causes the shingle 30 or 40 feet beneath the surface to emit a deep
rumble, had taken the unterseeboot in its grip.

Promptly the sea-plane wirelessed the news, and quickly a "general
call" was sent to the patrol vessels in the vicini