An expression of alarm crossed the detective's face.
"Is it injured badly?" he asked.
"I don't know yet. McCready says that the gauge is dropping pretty rapidly. I'm going to go out and see what I can do."
"Can't I go, Doctor? I'm a good deal lighter than you are."
"You're not as strong or as agile, Carnes, and you haven't the mechanical ability to make the repair. Hand me that line."
He fastened one end of a coil of manila rope which Carnes handed him to his waist, while the detective fastened the other end to one of the safety belt hooks. With a word of farewell, he climbed out of the cockpit and onto a wing. In the pocket of his flying suit he carried a tool kit and repair material. Carnes shuddered as the doctor's figure disappeared under the plane. He snubbed the rope about a seat bracket and held it taut. For ten minutes the strain continued. It slackened at last, and the figure of the doctor reappeared on the wing. Slowly he climbed into the cockpit.
"I've made a temporary repair, Lieutenant," he called into the speaking tube, "and the leakage has stopped. How much gas have we left?"
"Enough for about an hour of flying, including the emergency tank."
"Thunder! No chance to get back to the Denver. Better head inland and follow the course of the Dwina. If we can locate the place we are looking for we may be able to drop a few eggs on it before we are washed out. In any event, it will be better to come down on land than on water."
McCready headed the plane south and followed the winding ribbon below him which marked the channel of the Dwina. He kept his altitude well over eight thousand feet. For a few minutes the plane roared along. Without warning the motor sputtered once or twice and died.