Welsh British travel writer and memoirist Clare suffers from seasonal affective disorder: depression that “kills your power of vision, turning you fatally towards yourself.” In graceful, lyrical prose, the author recounts, in diary form, his descent into darkness, at the same time evoking vibrantly the sparkling wintry landscapes of Wales: swooping birds, silver birches against gray sky, glistening newly fallen snow. “A crow mobs a heron over the valley field, and on the canal Canada geese seem to glow, their soft colours enriched by snow-light,” he writes on Jan. 10. In March, the air seems “blue and dashing.” The contrast of natural beauty and inner turmoil makes Clare’s “heaviness of spirit” palpable. “In daylight,” he writes, “the bare trees reveal the country and its creatures in a clarity the other seasons deny. Cold winters do away with claustrophobia, and they are a gift to birdwatchers.” The author does not dwell on his symptoms (“no reader could have enjoyed them”) but keeps his diary as “a refuge, a thing to do, something to put work and time into, a defence against the hopelessness.” His defense entails reaching for happy memories—of joyful Christmases past, an ebullient childhood visit to Venice in winter, and the birth of his son, who happened to be born in January: “With Aubrey arrived, like a miniature immigrant from another planet, we saw the whole world anew.” Clare knows that others have found survival strategies for seasonal depression—“Bikram yoga, light boxes and counselling. Some dedicate themselves to cooking, cold-water swimming or medication”—but trapped in fear and self-loathing, he decided to seek a medical assessment. Fearing that he was bipolar, he is buoyed to learn that he is cyclothymic, experiencing normal rhythms, and likely to be helped by vitamin D, fish oil—and spring.