All My Sins Remembered

Otto McGavin works as a field agent for the Bureau of Political Assassination, an arm of the interstellar Confederacion tasked with eliminating threats before they surface -- and every mission means being handed a new personality, engineered onto his own, suited to whatever the job requires. The novel follows several such missions across Haldeman's linked stories, each one costing McGavin more of whatever self he started with, until the accumulation of borrowed lives becomes its own kind of horror. It reads less like a spy thriller than a study of what identity survives being used this way, again and again. A fix-up novel from early in Joe Haldeman's career.