Mendel’s Dwarf is an unusual piece. It’s a work of science fiction in the strict sense, but without any of the familiar traits of the genre. It is scientific literature in the literary sense but not the scholarly one; it’s a novel with footnotes that is in a hurry. Its narrator annotates his text with references because he is a scientist and that is how scientists write. But they do not write with the overtone of horror, and the unmistakable implication of looming disaster, that Simon Mawer sustains throughout his story.