"Just a heavy charge of static electricity," replied the doctor. "That was what magnetized your cylinder walls and your piston rings and slowed your motors down. It was the same thing that wrecked those two ships. Unless it leaks off, the men of some of your other ships are due to get a nasty shock when they land to-night. I discharged the charge we had collected through a ground wire. Here comes a car, we'll go up to Colonel Wesley's office. Carnes, you have these maps?" "Surely, Doctor." "All right, let's go." "But what about this ship, Doctor?" objected the General. "Can't something be done about it?" "Certainly. I hadn't forgotten it. Have your crew stand by. I'll telephone Washington and have some men with apparatus sent right down from the Bureau of Standards. They'll have it ready for flying in the morning. We'll also have search parties sent out in cars to locate the crews of those abandoned ships and bring them in. Now let's go." * * * * * Colonel Wesley, the commanding officer of the Aberdeen Proving Ground, welcomed Carnes and Dr. Bird warmly. "I'll tell you, General Merton," he said to the Chief of the Air Corps, "if you ever get up against something that is beyond all explanation, you want to get these two men working on it. They are the ones who settled that poisoning case here, you know." "Yes, I read of that," replied the general. "I am inclined to think that they are up against something even queerer right now." Colonel Wesley's eyes sparkled. "Give your orders, Dr. Bird!" he cried. "Since our last experience with you, you can't give an order on this post that won't be obeyed!" "Thank you, Colonel," said Dr. Bird warmly. "One reason why I came here was that I knew that I could count on your hearty cooperation. The first thing I want is two cars. I want them sent out to bring in the crews of two ships which were abandoned some eight miles south of here. Carnes will locate them on the map for your drivers." "They'll be ready to start in five minutes, Doctor. What next?" "Turn out every man and every piece of transportation you have to-morrow morning. I want the men armed. They will have to search a stretch of swamp south of here, inch by inch, until they find what I'm looking for." "They'll be ready, Doctor. Would it be indiscreet for me to ask what it's all about?" "Not at all, Colonel. I was about to explain to General Merton when trouble started. I am searching for the cause of the great drought which has been afflicting this country for the past two years. If I can find the cause, I hope to end it." "Oh! I had a sneaking hope that we were in for another skirmish with that Russian chap, Saranoff, whose men started that poison here." "I rather think we are, Colonel Wesley." General Merton laughed.