Beside the Ocean of Time is set in the Orkney Islands, on the fictitious island of Norday in the mid 1930s. First published in 1994, the novel follows Thorfinn Ragnarson, a boy whose imaginary adventures take us back in time to important moments in the history of the island. Bored with school, he is thought to be lazy and idle by his sisters, the schoolteacher, and others on the island. Thorfinn imagines himself accompanying a variety of characters on battles, quests, and other adventures in ancient times. Large sections of the text are made up of these adventures, narrated in a style similar to how myths are narrated in the ancient storytelling tradition.

One main storyline follows Thorfinn's childhood on Norday Island in the 1930s. It continues into his adolescence and early adulthood during the second World War. The narrator describes the simple village life with its crofts (farms), fishing, gossiping villagers, and quiet, daily life. Life on the island revolves around the land, the sea, the church, and the pub at the inn.

Thorfinn is disliked by the schoolteacher, Mr. Simon. Thorfinn takes history lessons and retells episodes from the island's history, as he plots these imaginary travels. He travels back in time to accompany a Swedish Viking ship, as it navigates through the Dneiper River in the eastern Baltic. With the crew, he travels to the kingdom of Byzantium. The group of travelers barely avoid being murdered at the court of prince Boris in Russia, but continue on to the Black Sea and then to the Emperor's court. It is here, that they are put into service as part of his personal guard.

In the next adventure, Thorfinn casts himself as an assistant to the Knight, Sir James MacTavish. The two travel south by horse to take part in the Scottish Battle of Independence at Bannockburn in 1314. Later, Thorfinn accompanies his school on a trip to visit the remains of a broch, an ancient stone tower. He imagines his next adventure, this time, as a poet/songwriter living in a Celtic village in the Dark Ages several thousand years BC. He writes a song to commemorate the building of the broch on Norday Island and honors the chief who has it erected. The brochs, built throughout the Northern Islands, protect them from invasion.

Thorfinn also tells the story of Jacob Olafson, who has recently died. Jacob grew up as a crofter. Thorfinn describes the man's life, including the highlights such as his disappearance on the day of his sister's wedding and his return from Canada ten years later, bringing with him a Native American wife.

Thorfinn grows from childhood into adolescence in the main storyline. A stranger comes to the island to visit the minister and the narrator describes quite a lot of the island's recent history through a description and explanation of the various reverends that have lived at the manse. The mysterious visitor is the current minister's sister, Sophie. Her presence is important to the island and though some islanders dislike her, she plays an important role in Thorfinn's life since she encourages him to be a writer.

Meanwhile, Thorfinn's father, Matthew Ragnarson, has been bringing up his son and three daughters alone at the farmhouse called Ingle. Tina Lyde, a local woman, attempts to win her way into Matthew's heart by bringing small gifts of homemade baked goods. Thorfinn's sister, Ragna, refuses to accept Tina into the household and sends the woman away, telling her she should never return to Ingle. Matthew does invite Tina to become part of the family. Thorfinn accepts her, as he joins her and his father for a meal she has prepared.

On the day of Ragna and Tina's argument, Thorfinn rides out to a hillside overlooking the island and tells the story of the arrival of the press gangs to the island. When recruiting officers arrive, looking to press young men into military service, the young men of the island go into hiding and outwit the press gang. During the islanders' celebrations, Thorfinn witnesses a group of Seal people dancing on the rocks by the edge of the sea. He takes a Seal woman as a wife and brings her home to Ingle, where she is accepted by his father, but resented by his mother. Thorfinn and Mara have many children, but eventually she disappears one day returning to her people.

Thorfinn leaves the island when a giant military operation transforms the island. Almost overnight, the military has destroyed both the land and the community. During the second World War, Thorfinn is captured and sent to a German prison camp, Stalag 29B. While he is there, he begins to write fiction. He sends novels to be published, with the help of a German officer, who lends him a typewriter and the Red Cross, who forwards the manuscripts to a publisher in London. While imprisoned, Thorfinn writes historical romances. The reader will recognize that the stories that Private Ragnarson writes are in fact, the same stories previously narrated in the novel.

After the war, Thorfinn returns to the deserted island of Norday. During the war, most of the fertile land and productive farmland was destroyed to make room for an enormous aerodrome used for defense against German attackers. Almost overnight, the entire community was changed, with large groups of workers, machinery, and concrete destroying the once placid and pastoral island. Thorfinn returns to Norday after several years spent living a wild and experienced, rich life in Edinburgh. After writing numerous romances, the author tries a different approach and writes a novel about "the impact on a primitive simple society, close to the elements, of a massive modern technology." This book brings him great success, but Thorfinn chooses to leave Edinburgh and return to live a simple life on the deserted island where he grew up. He returns to Norday, committed to living off the land and sea. Sophie joins him. The novel ends with the couple walking along the shore by the ocean, discussing how they will work the land and raise a son, who will be a poet.