The Night Manager - Penguin Modern Classics by John le Carré

To catch a criminal, he must become one.

Jonathan Pine, night manager of a luxury Swiss hotel, has a secret. He knows that the guest he awaits, billionaire trader Richard Roper, is ‘the worst man in the world.’ And he knows why. Pine will do whatever it takes to help the Intelligence services bring Roper down – even if it means going deep undercover into a ruthless, lawless world, up against forces more dangerous than he can imagine.