d came in violent contact with
the steel frame of the door, and, rendered senseless, he dropped
inertly upon the flooded floor of the passage.

"Pull yourselves together, men!" exclaimed the corporal to the two
prisoners. "You're all right. Bear a hand here."

Together they carried the unconscious master-at-arms out of the flat.
The corporal returned to liberate the occupier of the third cell--von
Hauptwald. But once again the keys were missing, having slipped from
the insensible man's hand.

The water in the confined space was now shoulder-deep. The corporal
could hear the stout bulkhead groaning under the pressure. Fixing the
lantern on a bracket he dived, groping with both hands for the keys.
At length he found them, and threw open the door of the cell.

"Out you come!" he shouted.

There was no reply. Von Hauptwald had ceased to shout for some
minutes. The silence was ominous.

A movement of the badly stricken ship sent the water well over the
corporal's head. He was swept off his feet. It was time for him to
get back to safety. He had done all he could. The spy was dead.

CHAPTER XXIV

"Shrap"

It was late in the afternoon when the _Oxford_ arrived, under her own
steam, at Rosyth. Although the dry docks were in use, accommodation
was quickly found for the damaged cruiser by the simple expedient of
floating out a battleship that was being cleaned and recoated with
anti-fouling composition. Since speed is an absolute necessity for
efficiency in war-time, it was the practice to dock all the ships of
the battle-cruiser and armoured cruiser class in rotation, the margin
of safety being sufficient to allow this to be done without impairing
the strength of the squadrons.

By the aid of powerful arc-lamps the dockyard hands took the crippled
_Oxford_ into dock, and, the caisson having been replaced, the water
was quickly pumped out. The damage done was found, on examination, to
be limited to a space extending 30 feet from the bows. The actual
aperture caused by the explosion measured 6 feet by 30 inches, but the
adjacent plates had been buckled and the bolts "started" under the
violent concussion. Well it was that the armoured bulkhead had
withstood the strain, otherwise nothing could have saved the ship.

There was no delay in setting to work. Almost before the last of the
water had been pumped out of the dock, stagings were built up round the
bows, and scores of shipwrights set to wor