Teena’s father seemed immensely impressed by Mr. Taylor’s reasoning. “It so happens,” he said, “that the blueprints we discovered missing today—added to the others—complete the entire layout of our new secret missile-guidance system. In the hands of an unfriendly nation, there’s no telling to what improper use the guidance system might be put.” “Then,” Mr. Jamison said, “this must be the end of their assignment—tonight’s delivery of the final blueprints.” “That’s right,” Eddie’s father said. “That’s how it would appear.” Mr. Evans came back into the room. “I’ve been arranging a little surprise party,” he said, with a rather tense smile. “I couldn’t help but overhear you, Mr. Taylor, while I was waiting for one of my calls. I think you’ve got that submarine angle pretty well figured out.” “I spent a hitch in the Navy,” Eddie’s father said, smiling. “Operating seagoing vessels—surface or subsurface—falls into a general pattern.” “True,” Mr. Evans agreed, “and I doubt very much that any submarine refueling tanker would be hanging around even several hundred miles out. Like aircraft traffic, shipping is run pretty well according to schedule. A wandering tanker would simply invite curiosity. But be that as it may, the immediate task is to capture that submarine—if submarine there is. We’re still going on guesses.” “What do you want us to do?” Mr. Taylor asked. “It won’t be necessary for any of you to do anything,” the FBI man said. “I’ve lined up all the assistance needed. Everything is set.” “You’re going to arrest those two men, aren’t you?” Eddie blurted out. “They—they’re traitors!” “They won’t go anyplace,” Mr. Evans assured him. “The important thing right now is that we don’t tip off our plans. Possibly they have various signals worked out with the submarine. Things have to go right on schedule, or we might lose the whole battle. Benton and Simms are small fish and can be landed any time we want. The big thing is the delivery of those blueprints and the isotope. That’s what we’ve got to stop.” The telephone on Mr. Taylor’s desk rang. “It’s for you, Tom,” he said, handing the instrument to Teena’s father. “File clerk?” Mr. Ross said, after listening a few seconds. “How about that! Thanks. No, don’t say a word to anyone.” He hung up, and turned to the FBI man. “Well, there’s your Roy Benton. A file clerk. New man. Been at Acme just a little over a month. Can’t figure, though, how he managed to get into the secret blueprint files. They’re kept locked up.” “Professional spies have ingenious ways of working,” Mr. Evans said. “Anyway, it’s pretty plain now how both the radioisotope and the blueprints happened to disappear. One thing’s equally certain. This is all part of a carefully worked out plan. The job now is to stop that plan—and stop it tonight.” “Oh, I’m frightened,” Teena said. “Spies, and submarines, and—and—”