"Strange substance for the lead to bring up," muttered Captain Brookes; then hailing the boat, "Get out the second grapnel; sound a couple of lengths further out, and report." The lead was again sent down. This time the cast revealed the presence of a dark ooze at seventy-four fathoms. Then the grapnel was set to work, but after traversing a short distance it became inexplicably entangled in some object. A third grapnel was lost in a similar manner. "There's something out of the ordinary down below," remarked the captain, as the result of the third dragging operation was announced. "I'm afraid we're beaten." "One moment, sir." Captain Brookes turned sharply on his heel and saw Lieutenant Palmer, pale yet self-possessed, standing close to him. "Well?" "I'm responsible for this, sir, and I hope to be able to rectify matters. Can I descend in the submarine?" "The submarine? You must be mad. Do you know the depth? Eighty odd fathoms, representing the tremendous pressure of 224lbs. to the square inch." "The submarine is tested to 230lbs., sir." "Much as I esteem your devotion, and much as I value the missing wireless gear, I cannot give my consent." "Sir, I know the risk, and will take every precaution. With the electric grab there is no need to descend to the extreme depth." "Mr. Palmer, I know you to be a levelheaded and calculating officer. I'm proud of you. If you will give me your word of honour to work cautiously, I'm willing to withdraw my refusal. Now, pick your crew; five men will be sufficient, and what is more, they must be volunteers, fully acquainted with the risk they are running." "I'm with you," said Gerald, calmly. "Thank you," replied Palmer, quietly, holding out his hand, which Tregarthen grasped firmly for a few seconds. It was a simple action, with a wealth of meaning behind it. Both men understood. The remainder of the volunteer crew were quickly forthcoming. The difficulty was to pick and choose, since every man capable of service in the submarine signified his willingness to take part in the enterprise; but at length Palmer, Tregarthen, and three seamen fell in on the quarter-deck as the heroes of a desperate venture. [Illustration: The searchlight revealed a huge circular turret with a pair of monster guns. Slowly the submarine swung round, the light travelling the length of the huge mass of weed-encrusted iron and steel.] Captain Brookes addressed them in a few words, urging the men to carefully consider the step they were taking. "You will," he continued, addressing Lieutenant Palmer, "descend for not more than one hour. If at the end of that time the submarine does not reappear I must take it for granted that some mishap has befallen you--which Heaven forfend. Meanwhile, all of you will do well to take a quarter of an hour's rest. Should any man, during that interval, think better of his decision, he may withdraw."