“Yes, sir.” Woolford said. He got up and examined the two bills again. “How'd they ever detect that one was bad?”

“Pure fortune. A bank clerk with an all but eidetic memory was going through a batch of fifties. It's not too commonly used a denomination, you know. Coincidence was involved since in that same sheaf the serial number was duplicated.”

“And then?”

“The reproduction was so perfect that Secret Service was in an immediate uproar. Short of the Nazi effort, there has never been anything like it. A perfect duplication of engraving and paper identically the same. The counterfeiters have even evidently gone to the extent of putting a certain amount of artificial wear on the bills before putting them into circulation.”

Larry Woolford said, “This is out of my line. How were they able to check further, and how many more did they turn up?”

“The new I.B.M. sorters help. Secret Service checked every fifty dollar bill in every institution in town both banking and governmental. Thus far, they have located ten bills in all.”

“And other cities?”

“None. They've all been passed in Greater Washington, which is suspicious in itself. The amount of expense that has gone into the manufacture of these bills does not allow for only a handful of them being passed. They should be turning up in number. Lawrence, this reproduction is such that a pusher could walk into a bank and have his false currency changed by any clerk.”

“Wow,” Larry whistled.

“Indeed.”