The fault in the conning-tower was quickly discovered. A small hole had been drilled in the steel column conveying the wires from the batteries to the indicator-board, and a metal rod had been inserted, thus causing a short circuiting of the current. The mystery was as deep as ever, for how did the miscreant find time and opportunity to make his way unobserved into the conning-tower and proceed to drill the thick metal standard? "There's hours of hard work in front of us," declared Captain. Brookes. "The disarrangement of this intricate mechanism is far more serious than one can imagine. Whether the ZZ-rays are similarly affected I cannot tell. We must find a clear field to undertake that experiment. However, we can do nothing more at present, as far as the conning-tower is concerned, so now for Slade's report." "All the reciprocators are missing, sir, except the Plougastel one," announced Lieutenant Slade. "That happened to be in the instrument." "Is the receiver damaged?" "No, sir; at least, I was able to communicate with Plougastel." "That's something to be thankful for," ejaculated the captain, fervently. "Though the loss of these reciprocators is irreparable. It means that we are cut off from all intelligence except by means of our Brittany agent. And now to interview Mr. Palmer." "Mr. Palmer is now in a sufficiently normal state to be interrogated, sir," said the surgeon. "He is still suffering from the effects of a narcotic--opium by the symptoms." "Very good, Mr. White," answered the captain. "I'll see him in his cabin." Lieutenant Palmer, looking utterly miserable, staggered to his feet and saluted as his captain entered. "Sit down, Mr. Palmer," said the captain, kindly. "Let me hear what you know of this business." Captain Brookes took a seat and waited for the lieutenant to pull himself together, giving a hasty, yet comprehensive, glance round the room as he did so. The cabin was small and plainly furnished. In addition to the ordinary "fitments," there was a small indicator on the wall which at present was showing a blue light. This signified that the wireless was not in operation, a red light giving the operator warning that his presence was required in the wireless room. On the table was a coffee pot and cup and saucer, large draughts of this beverage being beneficial in the treatment of opium poisoning; while on the floor stood a galvanic battery that Dr. White had used to a good purpose. "Now, Mr. Palmer." "I'm awfully, sorry, sir." "So am I, but up to the present you've done nothing to be sorry for as far as I can see. Pray proceed."