the spy who came in from the cold (1963)

Alec Leamas is offered one last operation after his Berlin network collapses. Set in the early Cold War, this short novel makes the official purpose of a mission compete with the human beings used to carry it out. Follow the recruitment and the changes in what Leamas can safely say. It is an excellent starting point for le Carré, with the consequences of the operation kept painfully close to ordinary loyalties.