The Hollow Nickel Case (or the Hollow Coin) was the FBI investigation that grew out of the discovery of a container disguised as a U.S. coin and containing a coded message, eventually found to concern espionage activities of William August Fisher ( Rudolf Ivanovich Abel) on behalf of the Soviet Union. Background On June 22, 1953, a newspaper boy (fourteen-year-old Jimmy Bozart), collecting for the Brooklyn Eagle, at an apartment building at 3403 Foster Avenue in the New York City borough of Brooklyn, was paid with a nickel (U.S. five-cent piece) that felt too light to him. When he dropped it on the ground, it popped open, revealing that it contained microfilm. The microfilm contained a series of numbers. He told the daughter of a New York City Police Department officer, and that officer told a detective who in two days told an FBI agent about the strange nickel. After agent Louis Hahn of the FBI obtained the nickel and the microfilm, the agency tried to find out where the nickel had come from and what the numbers meant. The coin had a 1948-dated obverse with the usual copper-nickel composition, but the reverse was minted sometime between October 1942 and the end of 1945, based on the copper-silver alloys used during this period. On the microfilm, there were five digits together in each number, 21 sets of five in seven columns and another 20 sets in three columns, making a total of 207 sets of five digits. There was no key for the numbers. The FBI tried for nearly four years to find the origin of the nickel and the meaning of the numbers. It was when KGB agent Reino Häyhänen ( Eugene Nicolai Mäki) wanted to defect in May 1957 from Paris, that the FBI was able to link the nickel to KGB agents, including Mikhail Nikolaevich Svirin (a former United Nations employee) and William August Fisher. Häyhänen was being recalled to Moscow for good, and defected on the way back in Paris. The deciphered message in the nickel turned out to be only a personal message to Häyhänen from the KGB in Moscow welcoming him to the U.S. and instructing him on getting set up. He gave the FBI the information that it needed to crack the cipher and uncover the identity of his two main contacts in New York (Svirin and Fisher), and a nearly identically made