“Dad,” Eddie said suddenly, “doesn’t everyone who works around the atomic lab have an identification badge with his picture on it?” “You’re absolutely right,” his father said, getting up quickly. “And we have duplicates of the pictures right here in our files.” He pulled a thick album from a steel drawer. He thumbed through to the ‘S’ section and opened it in front of Teena and Eddie. “That’s him!” Eddie said, pointing almost immediately to the picture of the thin-faced man. His name was listed as Harvey Simms. Underneath the photo the man’s job title was typed in a single word—Custodian. “Now I recognize him,” Mr. Taylor said. “I’ve seen him working around. A quiet person. The kind you hardly notice.” “That’s the way he would want it to be,” Mr. Ross said. Teena and Eddie went through the entire book of pictures without recognizing any as the man called Roy Benton. Mr. Ross picked up the telephone and called the Acme Aircraft Company personnel department. He gave Roy Benton’s name and the description Eddie and Teena had furnished. “See if you can get a line on such a person,” Mr. Ross instructed over the telephone. “Call me back as soon as you can.” He gave the number, and hung up. “Now, then,” Eddie’s father picked up the conversation again, “after managing to steal certain blueprints during the week, the men would naturally pick Saturday—their day off—to schedule the pickups by the submarine. We’re still assuming, of course, that a submarine actually is being used. It seems the only logical means of getting in and out past our alert Coast Guard. By timing the patrols, they would know when to surface. They would know how long to allow for their divers to row into the bay, get the tube, and return to the sub before the patrol doubled back. It’s possible, even, that the submarine carries a small seaplane. After returning to unpatrolled water, they could launch the seaplane to deliver the cylinder to some surface vessel, or possibly to an island or other land base. The submarine itself probably stays around for other pickups.” “Those are possibilities,” Mr. Ross admitted. “I mention it,” Eddie’s father said, “only because, if it’s true, the tubes which have been picked up off the sand bar are already delivered. In that case, your blueprints and my radioisotope are no longer secrets. If not, however, both still must be on the submarine. No sub could shuttle back and forth to a foreign shore fast enough to make delivery and get back within a week’s time. This is only a guess, but they may lie a few miles offshore during the week as a safety measure and to conserve fuel. They come in and surface just outside the bay each Saturday, under cover of darkness. When they have everything they’re after, they’ll head home. Since they already have sufficient samples of the isotope, my guess is that they are now after the final blueprints. The small samples of the isotope are now used only as tracers to help locate the submerged cylinders.”