At the heart of Natterjack is a relationship initially formed at a Scottish boarding school between Ronald and his older friend and confidant Maelbaetha (nicknamed MacBeth). Ronald has recently arrived at the school from Spain, and he is best described as a multiple self. In the course of his story, which he narrates from middle-age, Ronald's reflections subtly balance the similarities and contrasts between his self-absorbed adolescence and his retrospective adulthood, his native Spanish climate and the cold, damp Scottish winter he once found himself adjusting to, and the creative results of his adoption of an English vocabulary. More important, though, is another balance: his desire to tell MacBeth of his intense feelings and his equally strong (though only reluctantly acknowledged) wish to "choose a love for its very unhappiness". It is this psychological flaw that provides the key to the novel.
More than anything else, Natterjack is about being miserable, about the sort of hopeless yearning and loneliness and wilful self-destructiveness that never gets resolved. It is clear from the opening pages - where Ronald states that the act of writing is simple, an attempt to provide "an antidote to melancholy" - that he has forever remained locked on his past, and more particularly on MacBeth and the unspoken affection, an intimacy which was never superseded by other loves or commitments. From boarding school they went on to university, and from there into MacBeth's family firm. Despite eventual declarations of independent relationships, doomed attempts at psychological separation, and an at times unbearably uncomfortable intensity, they stayed together, separated only in the end by the death of MacBeth.
Because the outside world is conveyed through the interpretations and imaginings of Ronald's obsessive vision, Natterjack explores (again as in the later Henry James) the difference between events and the meanings we attach to them, the difficulties of grasping the significance of the gaps between thoughts and actions. This uncertainty is made more teasing by the lack of commitment by the narrator to a single opinion on any subject. Add the fact that there is also a great deal of literary allusion (Natterjack would appear to be, among other things, a reworking of Shakespeare's Macbeth), as well as much linguistic digression, and it will be no surprise that the novel is occasionally frustrating and obscure. But despite that, the publication of this unique and powerful novel is an event worth taking notice of.