Less than two hundred feet above Fort Medjidieh glided a large biplane. The motor had been switched off, for the crew had vol-planed down from a far greater height in order to make sure of their work.

"A Frenchman!" ejaculated Crosthwaite, for the tricolours on the under side of the main planes were clearly visible. "Hope he'll drop a couple of heavy bombs upon these ragamuffins. I'd be quite willing to the risk of any pieces hitting me."

The courtyard was now deserted, but from the doors and windows abutting on the open space, red-fezzed Turks peeped timorously, some of them plucking up courage to fire at the daring sea-plane. As for the crews of the anti-aircraft guns, they scurried off without letting fly a single round. The two German officers who had been conversing with the so-called Ahmed tried to restrain them, but in vain. One of the officers then began to train the nearest gun, but he, too, thought better of it, for holding his sword to prevent himself being tripped up, he ignominiously ran for shelter.

By this time the biplane had restarted its motor and was banking steeply. None of the shots fired at it had taken effect, nor did the aeroplane attempt to drop any bombs. Apparently its mission had been to chase the inquisitive Turkish monoplane, and to observe the nature of the defences of Fort Medjidieh. Having thrice circled over the hostile position with contemptuous indifference to the desultory fusillade, it returned towards its base.

Directly it turned tail the Turkish infantrymen and artillerymen issued from their shelters in swarms, and for five minutes—long after the French air-craft was out of range—a terrific waste of ammunition testified to the tardy zeal of the Ottoman soldiery.

During this time Dick saw nothing of Ahmed. The Teuton—for such he was—had made himself scarce. Nor did he put in an appearance during the rest of the day, the evening meal being brought in by a Nubian.

After breakfast on the following day the British officers were taken out for exercise under the escort of a file of soldiers. Their walk was limited to the extent of the courtyard, so that the Sub had no opportunity of taking mental notes of the details of the interior of the fort, for the heavy guns commanding The Narrows were hidden from sight by the barrack quarters.

Twenty minutes were allowed them. The Sub was able to smoke, some excellent cigarettes being given him by the corporal in charge of the party. At the expiration of the time the prisoners were marched back to their quarters, where they found Ahmed, unruffled and obsequious, awaiting them.

"Well, Ahmed," said Dick, with well-assumed jocularity, "we didn't see much of you yesterday. I thought perhaps you had been sent to take the captured British submarine to Constantinople."

The man looked completely taken aback. He suppressed an exclamation the commencement of which sounded remarkably like a German oath.