The Constant Gardener, written by John le Carré, is a gripping espionage novel set in the world of pharmaceutical companies and government surveillance. The story follows Justin Quayle, a British diplomat who investigates the murder of his wife, Tessa. As Justin delves deeper into the case, he uncovers a conspiracy involving a powerful pharmaceutical company and government surveillance. The Constant Gardener explores themes of corporate greed, political corruption, and the impact of surveillance on personal lives.