The subsidiary passage ran parallel to the eastern face of the fortress. At intervals there were large recesses converted into armoured casemates, each containing a 9-inch Krupp gun of a pattern of the early 'nineties. Since the ordnance on this side was intended solely for defence against a land attack, the guns were not so formidable as those enfilading the Dardanelles, yet the Sub realized that Fort Medjidieh would be a hard nut to crack if invested by an expeditionary force unprovided with the heaviest siege artillery.

At each casemate a line branched off from the main narrow-gauge track, showing that the tramway was originally intended to supply the heavy guns with ammunition. Making use of the rails for transporting torpedoes was the result of recent considerations.

Save for a few Turkish artillerymen who were lolling about, and who promptly made themselves scarce when they saw the German uniforms approaching, the gallery was deserted. Without actually meeting anyone, Dick and his companion reached the bend of the passage immediately under the south-eastern angle of the fortress.

Overhead the sounds of bustle and activity could be faintly heard through the massive steel armour-plate, additionally protected by a thick bank of earth faced with sand-bags. The purr of electric dynamos betokened the fact that the seaward search-lights were in full operation. Here the tramway dipped abruptly, egress being prevented by a heavy steel sliding-door.

"Rotten luck!" exclaimed Dick in a whisper. "Let's try that port-hole and see how the land lies."

The two officers made their way between the sliding carriage of the huge Krupp gun and the armoured wall of the casemate. There was just room enough between the chase of the weapon and the side of the embrasure for the Sub to wriggle. The walls here were not less than fifteen feet in thickness, and since the gun was "run in" there was enough space between the muzzle and the sill of the embrasure for both officers to observe the scene that lay before them.

Away on their right front was exposed a broad sweep of the Dardanelles, the swiftly-flowing water gleaming like burnished silver in the complex rays of the search-light. Almost immediately opposite were the outlines of Fort Kilid Bahr, backed by rugged hills towering to a height of nearly seven hundred feet.

Southward Fort Chanak reared its grim pile, from which search-lights innumerable swept sea, land, and sky, while fifteen or twenty miles to the southwest the sky was agleam with the flashes of heavy guns, showing that Sedd-ul-Bahr and Kum Kale were exchanging a vigorous cannonade with the ships of the Allied fleets.

Here it was that Dick made an important discovery. Fort Medjidieh was apparently not to be held in the event of a bombardment. It was to be used as a decoy to attract the British and French fire, while at a distance of not less than four hundred yards from the deep moat, rows and rows of deep, narrow, and zigzagged trenches were completed or in the act of being constructed.

Hundreds of Turks were busy, working by lantern-light, in digging themselves in, while the whole system of earthworks literally bristled with machine-guns. At the back of each trench, Dick noticed, were light canvas screens stretched upon wooden frames, and painted a similar colour to that of the surrounding soil. These screens were ready to be drawn across the trenches on the approach of hostile air-craft, In order that the observers would be unable to locate the position of the defences.