Two migrant workers, George and Lennie, have been let off a bus miles away from the California farm where they are due to start work. George is a small, dark man with "sharp, strong features." Lennie, his companion, is his opposite, a giant of a man with a "shapeless" face. Overcome with thirst, the two stop in a clearing by a pool and decide to camp for the night. As the two converse, it becomes clear that Lennie has a mild mental disability, and is deeply devoted to George and dependent upon him for protection and guidance. George finds that Lennie, who loves petting soft things but often accidentally kills them, has been carrying and stroking a dead mouse. He angrily throws it away, fearing that Lennie might catch a disease from the dead animal. George complains loudly that his life would be easier without having to care for Lennie, but the reader senses that their friendship and devotion is mutual.
He and Lennie share a dream of buying their own piece of land, farming it, and, much to Lennie's delight, keeping rabbits. George ends the night by treating Lennie to the story he often tells him about what life will be like in such an idyllic place. The next day, the men report to the nearby ranch. George, fearing how the boss will react to Lennie, insists that he'll do all the talking. He lies, explaining that they travel together because they are cousins and that a horse kicked Lennie in the head when he was a child. They are hired. They meet Candy, an old "swamper," or handyman, with a missing hand and an ancient dog, and Curley, the boss's mean-spirited son. Curley is newly married, possessive of his flirtatious wife, and full of jealous suspicion.