The Ambler Warning

In this thriller, a spy on the lam struggles to recover his memory and his sense of self. The government locked secret agent Hal Ambler inside a hospital for mentally ill patients judged to be security risks, but Hal is pretty sure he's sane. Given the chance to break out, Hal manages to find his way into the outside world--but, unfortunately, the drugs he was given have partially destroyed his memory, and to make matters worse, no one from his former life seems to remember him, either.