In <I>The Green Isle of the Great Deep</I>, Gunn continues the adventures of the two protagonists from his 1942 novel <I>Young Art and Old Hector</I>. The unlikely friends, representing the extremes of age and youth, are out on an undercover poaching trip when they become swept up in the currents of a salmon pool. When they awaken they have been transported from the Highlands of our world to an alternative Highland universe: a beautiful, fertile land called the Green Isle. Despite the abundance of the land, and the trees dripping with fruit, the population are subdued and miserable, ruled over by a strict upper class and forbidden to touch the fruit. Young Art, however, is not so easily controlled and his actions begin a chain of events which will change the Green Isle forever. Gunn draws many parallels in this tale, from the biblical references to Eden and the Tree of Knowledge, to contemporary commentary on the Nazi situation in 1940s Europe.