Molloy by Samuel Beckett is a novel written in two parts. In the first part, the titular character Molloy explains how he ended up bedridden at his mother's house. In the second part, a detective named Moran searches for Molloy and ends up falling further away from sanity in the process.

Molloy says he doesn't know how he got to his mother's room, though he lives there now. He believes someone—the same man who comes every week, maybe—brought him there possibly in an ambulance. The same man takes the pages he writes and brings him money for them, though Molloy insists that he doesn't write for money. He says he's writing this to say his goodbyes and finish dying.

Molloy isn't sure of his circumstances. He isn't sure whether his mother was dead when he got there or not but says he's taken her place. He says he might have a son somewhere but isn't sure. He tries to explain how he got to this point.

He was traveling to see his mother. After observing two people meeting from a distance, he was arrested for obscenity unfairly and then released. After he runs over a dog on his bicycle and kills it, the owner takes Molloy in its stead. Her name—and he's not sure she's a woman because of her hair—is Mrs. Lousse or Mrs. Loy. He thinks her first name might have been Sophie. He says that while he stayed with her, his physical ailments didn't get a great deal worse. Instead, they declined as he would have expected them to.

Once he leaves her house, he continues his journeys. Molloy beats a man and continues getting more and more ill. As his body breaks down, it's more difficult for him to make progress. Finally, he can't go any farther and stops in a ditch near the edge of the woods where he beat the man who enraged him. He sees a town in the distance but says he can't make out whether it's the town where he lives. Finally, he realizes that help has arrived. He remembers moments from his life as he lies there waiting to be rescued.

In the second part of the story, a man named Moran tries to track down Molloy. He was hired to do so by a man he doesn't know. He leaves with his son, also named Jacques Moran, to track down Molloy. As Moran travels, he becomes increasingly ill and less sure of himself. His prose, which was more clear at the beginning, begins to be less clear. He's unsure of what he's doing and what his motivations are.

Moran murders one man and then fights with his son when Jacques returns to his father. Alone, Moran wanders without an apparent destination. Once he returns home, he notes that he's been gone all winter and it's spring now. He thinks about his life and wonders whether he is freer now. He finds out his son is well and that the man who hired him is waiting for a report which should be written in the third person. He says he'll make sure he gets it. At the end, Moran's mind is obviously still very scattered.