A Strange Manuscript has two coinciding plot lines, the main one dealing with a British sailor named Adam More. More, who became shipwrecked on the way home from Tasmania, ventures in to a sort of late 1800's "Twilight Zone". Although it is described to be a real place on Earth, he finds an island where prehistoric animals that once roamed all of the Earth live. The island is kept running (in very cold Antarctic temperatures) by a volcano. On this island, he sees ancient plants, animals, and even prehistoric people.
Rather oddly, the people of the ancient world have values backwards to that of the normal world. Death is seen as a very good thing, and things like sickness and disease are revered as godly. The people also hate wealth, and the governmental system will punish them if they keep anything considered valuable
The second plot line is based on yachters who find the writings of Adam More floating in the ocean. As the title suggests, his writing was found in a copper manuscript, but they cannot decipher the language. However, it looks like it derived from a Semitic, Hebrew text, ancient in nature.