Pat signalled that they understood the contents of Tim's message, and the flying reporter zoomed the Sea King sharply in a farewell salute as he opened the throttle and roared back toward Key West. On the way back he sighted the _Iron Mate_ far to his right and a good thirty miles behind the _S-18_. If anything, the submarine was a good two knots and hour faster than the _Iron Mate_ when it was running on the surface. Tim reached Key West safely, saw that the Sea King was refueled and ready to go on short notice, and then went to the hospital to see the cook. Al Hardy was sleeping soundly and Tim continued to a hotel where he went to bed to get some much needed rest. It was late afternoon before he awoke. He made another call at the hospital, but was advised not to see the cook. After supper he went to a movie and then turned in early for with the dawn would come another long flight. During the night the wind subsided and ideal flying weather greeted Tim when he reached the waterfront. The sun was casting a rosy hue over red-tiled roofs and Tim welcomed the chance to soar into the cool, sweet morning air. The Sea King responded to the impulse of the starter with a roar and Tim flashed across the surface of the bay and into the air. He made a half circle into the west and lined away for a fast flight to overhaul the _S-18_. It was better than two hours later and fifty miles beyond their rendezvous when Tim finally sighted the submarine, sliding through the water at a strong twelve knots an hour. He brought the Sea King down to an easy landing and then taxied alongside the _S-18_, which was now lying motionless. Willing hands helped fasten the crane and its rigging to the seaplane and the craft was soon lodged safely on the deck of the submarine. Then they were under way again, the thin nose of the _S-18_ cleaving its way toward the sunken treasure in the hold of the Southern Queen. CHAPTER TWENTY Isle of the Singing Trees While Pat was on duty in the conning tower, Tim recounted in detail to Commander Ford just what had taken place in Key West. When he was through the Commander looked extremely grave. "Now that Sladek knows we are bound for an island off the coast of Yucatan, our only hope is for speed. It may take him several days to locate us after we are there, but with his seaplane he is certain to do that. We'll continue ahead as fast as possible and once over the wreck of the Southern Queen we'll lose no time in going down and getting what we can." Only Commander Ford knew the exact location of the island they sought off the coast of Yucatan. As the hours rolled into days, the tension aboard the _S-18_ grew. There had been no further sign of the _Iron Mate_ and they wondered whether Sladek was ahead or behind.