It is a bleak, Borgesian conceit and, though it is tempting to read the novel figuratively — as an allegory about global warming, or nativist isolationism, or Brexit — really, as Kavanagh himself is at pains to stress, the Wall should be understood literally ... quite different from anything [Lancaster] has written before and it is, I think, his best novel — though it has none of the sentence-by-sentence virtuosity of his earlier works. The story is told in flat, affectless prose, like that of JG Ballard in his pomp, but the overwhelming influence is the Kafka of The Trial and In the Penal Colony ... As with Kafka, though, it is hard to say what in the end it all might mean. The Wall could be about many things, but its real power stems from the fact that it never collapses into straightforward metaphorical equivalence. It asks only to be read on its own terms: as an unsettling, compulsive and brilliant portrait of powerlessness.
... if the novel succeeds only intermittently as a parable, it’s gripping as a story, especially when it leaves the Wall. As Lanchester puts distance between himself and his gigantic symbol, the plot grows less constrained, and the last hundred pages are full of tense action and sudden reversals that are mercifully unburdened by any allegorical significance. The result marks a step forward for Lanchester, a formidably intelligent author who has sometimes stumbled over his undeniable gifts ... For a certain type of realistic novelist, a shift to speculative fiction — which allows the writer to invent as well as observe — can be liberating. The Wall revels in this opportunity, but it occasionally falters under Lanchester’s decision ... The novel gathers momentum as it goes, and few readers will stop until they reach its final page.
Despite Lanchester’s affectless style, it is not tedious. As in making darkness visible, there is a skill in making the dull vivid ... a cracking adventure and an astute political fable ... Lancaster is a versatile writer ... The transparency of the book’s themes and style suggests that it is quite possible that he has deliberately chosen in The Wall to write a young adult novel rather than a complex literary fiction. This, anyway, is what he has done, and it is a very good one. Every secondary school library in the country needs to order a copy.