Ian McEwan’s latest novel, What We Can Know, is a profound meditation on memory, environmental culpability, and the limits of historical inquiry, wrapped in the guise of a literary detective story. Set against the bleak backdrop of a post-‘Derangement’ twenty-second century, the novel attempts to bridge vast ideological concerns with the close-quarters, high-stakes drama for which McEwan is famous. While the book ultimately rewards the patient reader with a gripping narrative payoff, its structural imbalance—a dense, meandering first half contrasted sharply with a clean, propulsive second—reveals the strain inherent in the author’s ambitious undertaking to fuse the intellectual with the intimate.

McEwan himself, in speaking about the novel, famously deemed it “science fiction without the science,” a description that perfectly captures the deliberate friction within Part One. The novel begins in the year 2119, in a water-logged, climate-ravaged Britain known only as an ‘archipelago’. We are introduced to Tom Metcalfe, an academic at the fictional University of the South Downs, whose professional obsession is the 'Derangement'—the twenty-first century, our present day, a time when humanity knew the impending environmental catastrophe but failed to act. Tom’s life is defined by scarcity and melancholy, providing a stark, post-apocalyptic frame for his scholarly pursuits.

Tom’s narrative, which occupies the entire first half, is a mosaic of fragmented details. His quest is highly academic: tracking down a long-lost poem, “A Corona for Vivian”, written during the time of the Derangement – the climate change plus nuclear war that was to change the face of the earth. This half of the novel is necessarily burdened by the weight of its thematic material. McEwan forces the reader to absorb heavy doses of world-building, fictional literary scholarship, and philosophical musings on the ethical vacuum of the past. Tom's intellectual curiosity, while theoretically compelling, often stalls the narrative engine, creating stretches where the book reads less like a thrilling quest and more like an intellectual treatise on post-catastrophe culture. His on-and-off romance and his random, ruminative thoughts about societal collapse and the remnants of lost civilization further interrupt the pace, frustrating the reader who is eager for the central mystery to unfold. The required “fictional makeup” of the early 22nd-century setting—the detailed descriptions of rising tides, resource rationing, the new library and archive systems, weird navigation of voyages in search of academic material—often feels perfunctory. These dystopian elements function primarily to establish the intellectual stakes of the present-day crisis rather than becoming fully integrated, organic components of Tom’s personal journey.

However, the deliberate structural nature of this slow buildup becomes apparent in the novel’s magnificent pivot. Part Two introduces the titular ‘Vivien’ and transitions abruptly into a tightly structured, deeply suspenseful narrative—a lengthy, unburdened first-person confession that is utterly captivating. Set in the present time, it is happily free of the sci-fi elements. This shift is like a sudden, welcome return to classic McEwan. The narrative, shed of its academic and dystopian obligations, takes off smoothly, transforming into a clean sequence of events featuring intense psychological suspense, murder, revenge, and moral consequence. The focus narrows from the fate of civilization to the betrayal between intimate companions.

Here, McEwan’s genius for psychological realism and moral complexity is fully unleashed. The prose is suddenly unbogged, focused, and precise, detailing a tangled love affair, a crime, and its cover-up that shatters Tom's earlier, scholarly assumptions about the past. This confession, rather than merely providing a final clue, delivers the entire, fleshy truth—the actual content of history that Tom’s academic tools could never grasp. It functions as a literary escape velocity, proving that the slow, information-heavy accretion of detail in the first half was essential ground for this explosive launch. The quiet despair of Tom’s future is perfectly offset by the messy, urgent passion of Vivien’s past.

Ultimately, the reader’s appreciation for What We Can Know hinges entirely on their tolerance for this initial structural drag. While the philosophical density of Part One provides the necessary moral and historical context—underscoring the terrifying distance between what we think we know and what we can actually recover from the past—it risks alienating those seeking immediate narrative drive. Had the novel been subjected to tighter editing in its opening sections, as one might argue, the story would have been immediately more suspenseful, but the contrasting emotional and intellectual weight of the two halves, and thus the overall profundity of the work, would have been diminished.

The hermeneutic question at the core, posed in the title, is what we can know – of a poem, of a person. All the academic interpretations of the key poem in the first part are overturned in the second, and so is the reader’s image of its protagonist.

The book stands as a testament to McEwan’s courage as an author, willing to test the boundaries of genre and structure. It is a powerful masterpiece—a novel that demands patience but ultimately delivers a searing commentary on human nature and the fleeting nature of truth across generations.