The letter enclosed a liberal draft on Professor Chadwick’s bank, and within forty-eight hours after receiving the missive which was to mean so much to them, the two cousins and chums, with the faithful Jupe attending them like a black shadow, were off for Galveston. On arrival there they went to the boatyard mentioned in the Professor’s letter, where they found the _Vagrant_,—the smart craft already mentioned as lying at the Lone Island wharf,—already equipped for sea, awaiting them. To install a wireless plant on board did not take long. The most difficult part of their task lay in finding a suitable mast for the support of the aerials. Jack solved this problem by constructing a telescopic staff of steel tubing which, when not in use, could be lowered to a height of twelve feet. In use it could be raised to an altitude of sixty feet, giving a very fair radius of scope. The materials for the wireless on the island, like those for the floating plant, had been brought from Boston. But the portable shack and bungalow were purchased in Galveston. The Professor’s letter had instructed the lads to wait on the island for a message by wireless. Now it had come; come, too, with a startling suddenness that might be likened to a jolt. Tom, watching Jack’s fingers with burning eyes, finally saw this message inscribed on the receiving pad: “Lone Island Station.—Proceed with all speed to Long. 96° W. by Lat. 27° N. Urgent. We are in dire peril.—Bangs, operator _Sea King_.” The patter of the electric waves against the receivers ceased. No further word came, and Jack, after a brief interval, took off the headpiece and laid it down beside him on the table. For an instant the message, so utterly, wildly different from any they had expected, almost deprived him of speech. Now his faculties rushed back, but he did not speak. Instead, he grounded the aerials by throwing the switch, and leaped to his feet with such impulsiveness that the stool on which he had been sitting went careering to the floor. “Come on, Tom,” he cried, darting for the door. As he ran he stuffed the message into the pocket of his linen jacket. Tom shot out of the shack after him. “You’d better lock——” he began. “Send Jupe to do it,” was the backward flung rejoinder, as Jack sprinted for the bungalow, “we’ve got to get grub on board and fill the water tanks within fifteen minutes.” “And then what?” “To sea—at top speed! The best the _Vagrant_ can do will be none too quick! They need us out there,” he flung his arm seaward in an embracing gesture, “need us mighty bad, and it’s up to us to make a record run to the rescue.” CHAPTER II—THE MYSTERIOUS X. Y. Z. “They said nothing as to what was the matter?” Tom propounded the question ten minutes later as the two lads busied themselves in the after cabin of the _Vagrant_, stowing provisions hastily. “No, not a word. If only I could have got in communication with them again I might——”