Niggle knows he must soon go on a long journey, but he’s reluctant to prepare for it. He’d rather focus on finishing his painting: a vast canvas with a huge tree and a background of forest and mountains. But he’s finding it hard to concentrate because his neighbor, Parish, keeps asking for favors. The laws of Niggle’s country order him to complete practical tasks and run errands, and Niggle doesn’t mean to disobey them, but he finds himself procrastinating the more mundane activities to make time for his painting.
One day, while Niggle works on his canvas, a man called the Driver arrives and orders Niggle to leave with him immediately: it’s time to begin his journey. Niggle has not prepared at all and can only take a small bag with him, containing some painting supplies and no clothes or food. The Driver takes him to the station, where he boards a train to the Workhouse. At the Workhouse, Niggle is assigned never-ending tasks involving hard physical labor. When he has worked to the point of exhaustion, the doctor orders absolute rest in the dark of his cell.
Niggle feels he’s been lying in the dark forever when he begins to hear two distinct voices. The two voices are debating Niggle’s quality of character, and whether he deserves to move on to the “next stage.” The First Voice is harsher, detailing Niggle’s many failures to help others or complete his tasks, but the Second Voice argues that Niggle made the best effort he could to follow the laws of his country. They decide that Niggle deserves to move on from the Workhouse.
The next morning, Niggle leaves the Workhouse and boards another train. When it stops, he alights to find a bicycle with his name on it. He rides it through the landscape and discovers, to his shock, that it resembles the land of his painting, including the huge tree, the forest, and the mountains in the distance. He feels the urge to tend to the land and to build a cottage and a garden—and he knows he needs Parish’s help to do so.
As if summoned by Niggle, Parish appears nearby. Together they begin to cultivate the land and build the cottage. One day, after they have finished their work, Niggle decides he will go on a long walk. Parish goes with him. They walk until they reach the foot of the mountains, where a shepherd comes down to meet them. Niggle knows it is time to follow the shepherd into the mountains; Parish stays behind to wait for his wife.
Back in the old country, some of Niggle’s acquaintances argue about the significance of his work. Councillor Tompkins declares Niggle’s paintings of the natural world to be useless, but Atkins decides to frame a single leaf from Niggle’s tree and frame it, later donating it to the Town Museum. The Museum is burnt down, however, taking with it the final trace of Niggle’s life. Meanwhile, the two Voices decide it’s time to name the land of Niggle’s painting, where they’ve been sending more and more people to convalesce after their time in the Workhouse. It transpires that the Porter has already decided upon a name: “Niggle’s Parish.”