The Constant Gardener is a suspenseful novel by John le Carré. The story revolves around Justin Quayle, a British diplomat who investigates the murder of his wife, Tessa. As Justin delves deeper into the case, he uncovers a pharmaceutical conspiracy involving surveillance, corruption, and exploitation. This thought-provoking book explores themes of corporate power, government surveillance, and the lengths one man will go to uncover the truth.