"Counter-Terrorism in a Police State: The KGB and Codename Blaster, 1977," by Mark Harrison, is No. 59 in the PERSA series. The paper is based on files of the Lithuania KGB newly acquired by the Hoover Institution. It provides a rare case study of terrorism and counter-terrorism within a closed society, carried out under a blanket of official secrecy. This case is unexpectedly revealing in what it tells us about terrorism, counter-terrorism, and the relative strengths of open and closed societies. Documents from the archive of the Lithuania KGB show how the Soviet authorities managed the hunt for the perpetrators of bombing attacks carried out in Moscow in January 1977. Lithuania, a sensitive border region with a troubled history, was far distant from the epicenter of the conspiracy in Soviet Armenia, but the authorities did not know this beforehand, and made considerable efforts to establish or rule out a Lithuanian connection. It was a problem that the KGB, like other Soviet organizations, was vulnerable to box-checking and other kinds of perfunctory working to the plan. The career concerns of regional KGB leaders appear to have countered this tendency. The paper evaluates the strengths and weaknesses of a counter-terrorist operation carried out under conditions of the intense secrecy that was normal in the Soviet police state. The paper is available free of charge from www.warwick.ac.uk/go/persa.