Hythe, still resisting, saw the action.

"I wonder what he's up to?" he muttered. "Going to puncture my suit, I suppose, and half-drown me. Take that, you under-handed rascal."

With a sudden wrench he freed his right hand, and clenching his fist hit madly at the diver's front plate. Had the blow struck home the glass would in all probability have been broken, but the man stepped backwards and the sub's fist encountered water only. That attempt led to Hythe's undoing, for two stalwart fellows seized him by the arm of his india-rubber suit between wrist and elbow. Held as in a vice he was unable to draw back his hand, the diver with the fork-like instrument immediately applied the points to the officer's bare knuckles.

A powerful electric current passed through him. He writhed; his limbs jerked with uncontrollable spasmodic movements, till, his spirit literally cowed, he was unresistingly carried through the aperture in the side of the submarine.

The panel glided to, smoothly and easily, leaving the compartment in utter darkness. Then came the sound of powerful pumps at work, and soon, by the weight of his helmet, Hythe realized that the water was being expelled. Within a minute and a half of the time of entering the place the sub was no longer in the sea, although he was under it.

A bell rang and another door opened, revealing a fairly spacious compartment well lighted by electricity. The floors, walls, and ceiling were of metal coated with a substance resembling coarse cement. Along one side were racks and pegs to take the diving equipment, several complete suits being not then in use. On the other side were coils of rope, lengths of chain, oars, grapnels, boathooks, and other gear used on board ship, while a folding canvas boat in three detached sections occupied a considerable part of the available space. On the bulkhead in which was the sliding-door by which Hythe and his captors had entered the compartment were various switches for controlling the ejecting pumps, the intake valves, and the lighting of that section of the vessel. In the other transverse bulkhead was also a door, fitted with a watertight sliding hatch. On either side of this doorway were complicated machines of which Hythe could neither make head nor tail.

Feeling more like a thoroughly cowed puppy than anything else he could liken himself to, the sub was divested of his diving-helmet and suit. The former was placed on the rack beside the others, the suit, not being of the same pattern as that of his captors, was hung up apart from all the rest. All this while the divers retained their head-dresses. They did not even remove the glass plates. As soon as the sub was free from the encumbrance of his diving-dress three men entered from another compartment.

They were tall, broad-shouldered fellows, clean-shaven, and with dark crisp hair. From their appearance they might be near relations, possibly brothers. They were clad in dark-blue jerseys and trousers, and dark canvas shoes, and looked more like yacht hands than the crew of a submarine.

"The captain will be pleased to receive you, sir," announced one in good English, with a west-country accent that a foreigner could not possibly acquire, saluting as he spoke. "What name shall I give, sir?"

The young officer hesitated a moment, then, reflecting that it was of no use beating about the bush, replied, "Arnold Hythe, Sub-Lieutenant of H.M.S. 'Investigator.'"