" him a deal, give him twenty thousand in marked bills to buy coke from his supplier, then catch the bigger fish holding the government’s money.” “What if you don’t catch the crook?” Ray asked, and in doing so could not help but think of his departed father. “That’s the second way, and it’s much more difficult. Once the money is lifted out of circulation by the Federal Reserve, a sample of it is routinely scanned. "

― John Grisham , The Summons