The sub had no compunction. Although he could not under present circumstances summon the man to surrender in the King’s name, he realized that, by virtues of the special Act of Parliament, he was authorized to summarily arrest any member of Captain Restronguet’s command. The next instant the two divers were locked in a close embrace, Hythe endeavouring to bring the man’s arms to his sides, while at the same time he shouted through the telephone for his comrades in the boat to haul him to the surface. The unknown struggled desperately, striving to pass one heavily-leaded boot behind the sub’s ankle. For ten seconds they grappled in the eerie depths of the sea, then Hythe found himself being dragged along the sandy bottom. His signal to be hauled up was being answered, and the steady strain on the life-line told him that unless anything unforeseen occurred another minute would find him and his captive at the surface. On and on, over the yielding sand the two men were dragged, for the long scope of rope prevented an immediate upward ascent. Suddenly the unknown diver wrenched one hand free. He drew his knife, the blade glinted dully in the pale green light, and with a steady motion severed the life-line. "Great heavens! He’ll sever my air-tube next," thought the sub, but, apparently content with the advantage already scored, the fellow dropped his knife and tightened his grasp upon his antagonist. "Blow me up!" gasped Hythe through the telephone, but although the men at the air-pumps redoubled their exertions the extra pressure of air escaped through the valve in the young officer’s helmet, since he was unable to close it. "I am attacked. Tell O’Shaunessey and Price to come to my assistance," exclaimed the sub. In spite of his powerful physique he was not even holding his own. He had bitten off more than he could chew. During the struggle the sand churned up by the feet of the wrestlers rose till it was almost impossible to see more than a few feet away. Several times Hythe gave a hasty glance to see if his men were coming to his aid--but no. Four grotesquely-attired figures appeared through the sand-blurred water. With a feeling of dismay the sub realized that he was hopelessly outnumbered. Since he had taken the initiative in provoking the contest he knew that he must expect to accept the consequences; yet he determined to resist as long as his strength of body and mind remained. Powerful hands grasped him by the arms and legs. He was overthrown and lifted into a horizontal position. Even then he kicked out strongly till his captors, having good cause to fear his leaden-soled boots, desisted in their efforts to secure his legs. A loud buzzing--the hiss of escaping air--told him that the worst was at hand. The minions of Captain Restronguet were unscrewing the union of his air-tube. CHAPTER VI. FACE TO FACE.