Peter Wright was asked in 1954 to join MI5 formally as its first science officer, though he had been providing technical aid and information for several years, and he worked there until his retirement in 1976. Wright’s insider’s view is fascinating: the personalities of senior officers, the infighting between MI5 and MI6 (the Special Intelligence Service, responsible for collecting foreign intelligence), Wright’s interrogations of Anthony Blunt, the methods of collecting and analyzing information.

Wright’s first years at MI5 were marked by advances in various methods of electronic eavesdropping, accomplishments that were personal triumphs for Wright and that often yielded valuable information, yet the greater part of SPYCATCHER concerns Wright’s long search for a high-level mole within MI5. His investigations convinced him that the director of MI5, Roger Hollis, was a long-standing Soviet spy. This allegation, however, has never been proved. The reader becomes intrigued and baffled by Wright’s efforts in the “wilderness of mirrors,” sorting through the varying interpretations that can be given to a single fact, yet, by the end of SPYCATCHER, one begins to wonder whether Wright is the British James Angleton, obsessed with finding betrayal where there is none.

Wright’s account, though basically chronological, often skips back and forth in time as one incident reminds him of another, and this can confuse the American lay reader trying to keep straight the plethora of initials and code names that can make a page of SPYCATCHER look like alphabet soup (a glossary and an index help). Wright also assumes a rather detailed knowledge of recent British history that many Americans may not have. Wright’s bitterness over his failure in the Hollis case and over his parsimonious pension show through, and one begins to take his words with a grain of salt, but one nevertheless continues to read, shocked by such allegations as that a group of MI5 officers sought ways in which to oust Harold Wilson as prime minister, considering him a security risk because of his choice of friends.