Almost in an instant Denbigh decided how to act. He could have crept along the alley-way and surprised the sentry; but stunning the man would be of little use. Nor could he hope to bluff the fellow, since there was too much light to attempt to pa.s.s himself off as one of the _Pelikan's_ officers. To retreat was impracticable, for someone, he knew, was on deck in the immediate vicinity of the companion.

Without hesitation the sub opened the door of the cabin adjoining his and entered quickly and silently. The place was in darkness. Whether it was tenanted or not he was unable to ascertain. Closing the door he stood stock-still and listened. He could hear no sound of a person breathing. For five minutes he waited, then began to grope until he found the edge of one of the bunks. The sleeping-place was empty.

There were not even blankets and bedding. This looked promising.

He continued his exploration, testing the remaining bunks in turn, until he was able to come to the happy decision that by sheer good luck he had lighted upon an empty cabin.

The gla.s.s scuttle in the port-hole was closed, but there was no dead-light in position over the opening. In that case it would be too risky to switch on the light, until he had taken due precautions.

The dead-light squeaked shrilly on its hinges as he drew it to. He wondered whether the watch on deck heard the sound. He waited again.

There were many footsteps descending the companion. He could detect von Langer's guttural tones, discussing some matter with one of the other officers.

"Dash it all!" e.j.a.c.u.l.a.t.ed Denbigh, a cold perspiration standing out on his forehead. "What if I'm in that fellow's cabin?"

The men stopped outside the cabin. They were evidently indulging in horse-play, for once a heavy body struck the wall with a thud, followed by a chorus of boisterous laughter.

Then, to Denbigh's intense relief, the officers went along the pa.s.sage.

Once again he had been lucky.

Rea.s.sured he switched on the light. The cabin was bare of furniture.

In one corner lay a pile of books and a couple of sea-stained portmanteaux. Hanging from a coat-hook was an officer's sword-belt.

It was mildewed; the st.i.tching of the holster had burst, the buckle was green with verdigris. Attached to the belt was a small, circular leather case secured by a strap.

Denbigh handled it gingerly. There was something hard inside.

Curiosity prompted him to unbuckle the strap and open the case. Within was a pocket-compa.s.s. What was more, it was a spirit one and seemingly in good order. Without compunction the sub abstracted the compa.s.s and slipped it into his pocket.

As he did so he was startled to hear a deep groan. It seemed to sound close to his ear. He wheeled abruptly and shot a glance in the direction of one of the bunks, thinking that he had made a mistake in deeming it untenanted.

There was no one there. Again the groan was repeated. This time the sound seemed to come from the adjoining cabin--the one occupied by Pat O'Hara.

A hole in the bulkhead attracted Denbigh's notice. It was the aperture drilled by the Germans when they made their ineffectual attempt to chloroform the three British officers.

Through it Denbigh could see but a very small portion of the next cabin, but sufficient to observe O'Hara lying on his back in his bunk.

He was writhing and groaning. His eyes were wide open and rolling in a horrifying manner.

Outside all was quiet once more.

"I say, old man," whispered Denbigh. "What's wrong?"

At the sound of his voice O'Hara raised himself. He tried to speak, but could not. With an effort he rolled out of his bunk and stood clinging to the edge for support.

"Open the door," said Denbigh peremptorily. "I cannot get in."

"If he's not able to it's the last straw," he soliloquized. "I'll have to give myself up and get a.s.sistance."

With a great effort the Irishman lurched across the floor and removed the chair which had been wedged against the lock. Then, unable to regain his bunk, he pitched inertly upon his face.

Denbigh waited no longer. He darted into the alley-way, not even waiting to see if everything were clear. The door opened easily. He entered, and lifting O'Hara as easily as a child placed him on his bunk.

"Felt jolly rotten almost as soon as you cleared out," muttered the Irishman. "Sorry, but I couldn't help it."

"I don't suppose you could," replied Denbigh, for O'Hara's regret was genuine. "I'll ring for a.s.sistance."

He touched the electric bell. Then, and only then, he remembered that he had to replace a portion of the lock. Grasping the screw-driver he set to work, and had just driven home the last screw when the locked turned, and a petty officer entered.

The man hurried off for the ship's surgeon. It was nearly a quarter of an hour before the doctor arrived. He came prepared to deal with a trifling case, but when he saw the Irishman he looked grave.

Without expressing his opinion the surgeon went out. Nor did he again put in an appearance. He sent, however, some quinine and written directions as to treatment.

For the rest of the night Denbigh sat up with his comrade. As day broke O'Hara seemed easier. The internal pains pa.s.sed off. His temperature fell. He was able to talk rationally. By noon he was practically well again. The attack had been sharp and rapid, but once over it seemed to leave no ill-effects.

Without being sighted by any of the British patrol vessels the _Pelikan_ and her prize arrived off the entrance to the Mohoro River.

Here the two ships slowed down until there was sufficient water for them to cross the outer bar.

During the interval Denbigh and O'Hara were peremptorily ordered to leave the _Pelikan_ and take up their quarters on the _Myra_, the reason being that von Riesser was terribly afraid of illness, and in spite of the doctor's a.s.surances he had a firm belief that O'Hara was suffering from yellow fever, malaria, black-water fever, and every tropical disease under the sun.

"Let him jolly well think so," said the Irishman joyfully. "I feel as fit as a fiddle now; and I'm not sorry for the change."

All the same O'Hara acted the invalid to perfection as he was rowed from the raider to her prize. Denbigh accompanied him, taking good care to bring all their scanty personal property that they had been permitted to save from the _Nichi Maru_, excepting the gold that von Riesser had ordered to be confiscated.

The _Myra_ was in charge of Unter-leutnant Kaspar Klick and fifteen men. There were also the skipper, officers, and crew of the tramp, numbering thirty-two persons. The officers were given a fair amount of liberty, but the men were kept under hatches, to their no small discomfort in the tropical heat.

"Sorry I'm not able to make your acquaintance under more favourable auspices," was the greeting of Captain Pennington, the master of the captured _Myra_, when the two subs introduced themselves. "But I hope before many hours that we will be set at liberty."

"We've been hoping that for weeks," said Denbigh. "The luck those fellows get is astonishing."

"So I should imagine," agreed Captain Pennington. "I learnt at Cape Town that the _Pelikan_ was given up as lost, as some wreckage and one of her boats were picked up in the South Atlantic. That is why our cruisers relaxed their patrol, and were ordered to rendezvous at Zanzibar. There'll be a dozen or more on their way up."

"And any monitors?" asked O'Hara.

"Four, as far as I know," replied the _Myra's_ skipper. "One was detained for repairs at Simon's Bay. The others must be at Zanzibar by this time. They will be invaluable for work inside the coral reefs."

"And the _Pelikan_--or _Zwaan_, as we are accustomed to call her--hopes to ascend the Mohoro River. Her draught is about twenty-two feet, and she may be able to lighten to eighteen."

"She won't do it," declared Pennington decisively. "It will be as much as she can manage to cross the outer bar. She'll be nabbed before she does that."

"When's high water?" enquired Denbigh.

"Let me see. New moon's on Friday. To-day's Sat.u.r.day. High water, full and change, is at 4 p.m. I take it that it's the top of the tide to-day at eleven or thereabouts. They'll have to be pretty sharp about it to arrive off the entrance to the lagoon by that time."

As a matter of fact von Riesser signalled for the prize to steam full speed ahead, the _Pelikan_ following at four cables' lengths astern.

By 8.30 the _Myra_ slowed down off the entrance to the Mohoro River.

There was a considerable amount of mist about, for the land breeze had not commenced to make its influence felt.

All that could be seen was a long, irregular line of coral reefs against which the ground-swell broke with a sullen roar into ma.s.ses of milk-white foam. There were nearly a dozen visible gaps in the reef, the largest, bearing directly ahead, being marked by a couple of coco-nut palms.

At this point an island was in course of formation, there being a few feet of soil acc.u.mulated upon the coral. These trees marked the entrance to the lagoon, into which the Mohoro River made its way by means of three separate estuaries.