When daylight came the captives could scarcely believe that the events of the preceding night had not been all a dream. There was the document, however, to prove their reality, and Guy was deeply studying its faded characters when the Greek arrived.

His face was radiant with happiness, an expression which quickly gave way to deep sadness as a big Somali entered with a platter of food. The latter had barely closed the door when Canaris held up a warning finger and motioned the Englishmen to draw near.

“It is well,” he said softly. “I will tell you what I have done. Near the palace lives a Jewish merchant whom I know well. To him I went last night and by the aid of your gold made a good bargain. On the western side of the city, close by the wall, is a deserted guard-house that was once used before the watch-towers were built. Here the Jew promised to take for me the goods I purchased ­namely, a supply of dates, figs, and crackers, three revolvers, three rifles with boxes of shells, three sabers, two ancient bronze lamps with flasks of palm oil, a box of English candles, and four long ropes with iron hooks on the end.”

“He will betray you to the Emir,” said Guy in alarm.

“Oh, no,” returned Canaris, “no danger of that. I know a little secret concerning my Jewish friend that would put his head above the town walls in an hour’s time. The things are even now hidden in the deserted house, you may rely on that.”

“But how are we going to get out of this infernal dungeon?” asked Guy. “And how can we pass through the streets to the edge of the town?”

For answer the Greek opened the leather case that he had brought with him and took out three revolvers, three boxes of shells, a coil of rope, and a sharp knife.

“These are my surgical instruments,” he said. “I will put them under the straw,” and he suited the action to the word.

“Affairs outside have changed somewhat,” he continued. “The people are sullen and restless. They mistrust the Emir, and fear they will be cheated of the pleasure they are looking forward to.”

Guy turned pale. “Then we are lost!” he cried.

“No, you are saved,” said Canaris. “That very fact works for your salvation. The Emir is alarmed; he fears for himself, not for you. His troops are few since he despatched the caravan to Zaila, and at night, for better security, he takes guards from the prison courtyard and stations them before the palace. This leaves three guards to contend with; one watches in the corridor, one stands before the prison door, and the third guards the gateway that opens from the prison yard on to a dark avenue of the town. If all goes well you will be free men at midnight. I must hurry away now. Listen well to my instructions, and do just as I tell you.

“You,” and he turned to Melton, “must pretend that your wound is bad. Refuse to eat and lie on the straw all the time. It will be better if I do not return today. I fear that even now Rao Khan grows suspicious. The Arab doctor is angered because I have assumed his duties. At midnight, if you listen sharply, you will hear the guard relieved by a new man. Soon after that knock on the door, and when the guard looks in show him the wounded man, who will then feign to be very bad. I sleep in a rear apartment of the palace. The guard will send for me, and I will come. Otherwise my visiting you at that time of night would be looked upon with suspicion. The rest I will tell you then. Don’t despair. All will be well; till midnight, farewell.”

Canaris glided from the dungeon, and the prisoners were alone. They passed the long hours of that day in a strange mixture of hope and fear. The difficulties to be overcome seemed insurmountable. They must escape from the prison, pass through the very midst of their bloodthirsty enemies, scale the wall, and then ­where were they? Hundreds of miles from the coast, surrounded by barbarous and savage people, and their only hope that mysterious underground river which in itself was a thing to be feared.

But, on the other hand, speedy death awaited them in the dungeon of Rao Khan. The chances were truly worth taking.

They followed instructions closely when the guard brought them food at noon, and in the evening Melton tossed on the floor as though in pain. The thrice-welcomed darkness came at last, and the light faded out of their dungeon. Once a horrible thought entered Guy’s mind. What was to prevent the Greek from making his escape alone, and abandoning the Englishmen to their fate? It was but momentary, however, and then he dismissed the suspicion with a feeling of shame. He had already learned to trust the Greek implicitly.

Crouched by their dungeon door, they listened by the hour, and at last their patience was rewarded. Voices were heard, steps approached and died away, and then all was silent.

The time for action had come.

Melton threw himself on the straw and moaned. Guy rapped sharply on the door and waited in suspense. Almost instantly it opened, and the guard, a tall Nubian, pushed his lamp into the doorway and followed it up with head and shoulders.

“Canaris, Canaris!” said Guy earnestly, pointing to Melton, who uttered at that moment a most unearthly groan.

The guard drew back and shut the door. His soft tread echoed down the corridor, and all was still.

The suspense of the next five minutes Guy will never forget as long as he lives. It seemed to his excited imagination as though an hour had passed by, when suddenly sounds were heard in the corridor, and in an instant more Canaris stood before them, his leather case at his side, a lamp in his hand. He closed the door, opened, the case, and drew out two wide linen tunics and two long jackets such as the Émir’s troops wore.

“Put these on,” he whispered. “You can wear your helmets; there are many of them in Harar.”

As he spoke he drew an Arab burnous over his head, shading entirely his light hair and mustache. He next pulled the revolvers and shells from under the straw, distributed them around, and with the knife cut the rope in a dozen parts. By this time Guy and Melton had donned their disguises and were ready for action.

Up to this point Guy had supposed that Canaris had bribed the guards and paved the way out of prison.

“You are sure the guards will let us pass?” he said.

Canaris looked at him in wonder, and then a smile rippled over his face.

“You thought I had bribed the guards,” he said. “Ten thousand pounds could not tempt them. They would only lose their heads in the morning. It matters little,” he added. “They will lose them anyhow. But our time has come; be ready now to assist.”

He motioned Guy and Melton behind the door, and then, pulling it partly open, uttered a few words in a strange tongue.

Instantly the powerful frame of the big Nubian entered, and as he stood for one second on the dungeon floor, sudden mistrust in his ugly features, Canaris leaped at his throat and bore him heavily to the ground.

“Quick!” he cried, and in an instant Guy and Melton had seized the struggling man’s arms and feet.

Still pressing the fellow’s windpipe with one muscular hand, Canaris thrust a gag into the gaping mouth, and in two minutes their captive was lying bound and helpless on the straw.

“What did you tell him?” asked Guy.

“I said our lamp was going out,” Canaris replied. “And now for the man at the prison door. I must get him inside, for the post is in plain view of the guard at the gate.”

A solution of this puzzling problem was closer at hand than anyone imagined. The creaking of a door was heard, followed by approaching footsteps.

“Here he comes now!” said Canaris in an excited whisper. “He has grown suspicious, and has determined to investigate. Quick!”

Canaris darted to the other side of the doorway, and then ensued another period of chilling suspense.

The tread came nearer, and at last another stalwart Nubian blocked the doorway with his massive bulk. His look of wonder was comical as he saw his comrade gagged and bound on the dungeon floor, but before the half articulated exclamation could escape his lips Canaris had him by the throat, and down they came. The fellow uttered one cry, and then, as his head struck the edge of the door in falling his struggles lessened, and with no trouble at all he was gagged and bound.

Canaris tore the ammunition from their belts, handed Guy and Melton their rifles, and then, blowing out the lamp, he pushed them into the corridor and bolted the door.

“Two heads will be off in the morning,” he remarked grimly. “One more victory and we are out of prison.”

He blew out the light that stood in the corridor and led the way through the darkness till he reached the door. He pulled it open, a crack revealing the moonlit courtyard, and took a long, careful survey.

“There is the man we want,” he whispered, pointing across the court, and putting his eyes to the crevice Guy saw against the massive prison wall a dark shadow leaning grimly on a rifle.