Mr. Evans seemed to have caught the exchange of glances. “Remember,” he said to Eddie, “I mentioned that we should have no trouble grabbing them whenever we wanted to. Well, we got them. A few others, too. Simms and Benton were sitting outside that old fisherman’s shack, still holding the battery lantern they used to signal the submarine.”

“Boy, oh, boy!” Eddie exclaimed.

“Now, gentlemen,” Mr. Evans went on, turning to the main group, “please regard all that is said here as confidential until it is officially released through the proper channels. If you are wondering why these two young people are sitting in on this hush-hush session, I take great pride and pleasure in informing you that, without their alertness and curiosity over certain suspicious actions, that submarine might now be on its way seaward carrying two secrets very precious to this country’s security.”

Eddie blushed but felt mighty good. Teena looked at her hands, trying to hide the pleased smile on her lips.

“Mr. Taylor and Mr. Ross,” the FBI man said, “this should also please you. We found two more of those sealed metal cylinders inside the submarine.”

“Then they hadn’t delivered them!” Eddie’s father said with obvious relief.

“That’s right. In fact, the submarine commander has admitted that they have been lying about thirty miles off the coast during the week. Tonight was their third trip to the bay. Incidentally, it was scheduled to be their last. They had plenty of the secret radioisotope, and today’s blueprint delivery completed the main set on the new missile-guidance system they also were after. If we hadn’t set the trap tonight, we would have been too late—another reason for appreciating the alertness on the parts of your son, Eddie, and Mr. Ross’s daughter, Teena.

“Now,” Mr. Evans continued, “we haven’t had time to solve who was behind all of this, or why. We have our ideas, of course, but it’s going to take considerable investigation to draw a full and clear picture. At the moment, I’m not free to reveal to what country that submarine belongs. I did think, though, that you two gentlemen deserved to know that the isotope and the blueprints are safe.”

“It will be a long time, I imagine, before either Mr. Ross or I will hear better news,” Eddie’s father said.

“In order not to delay nuclear research, nor to hold up production at Acme Aircraft,” the FBI man said, “we’re sending the tubes with you under armed guard to your laboratory, and you can take over from there.”