The boy next to me left in the interval. People are strange. From curtain-rise to close, I was riveted by Francis Turnly’s new historical drama. In 1979, a spirited 17-year-old named Hanako (Kirsty Rider) disappears on a Japanese beach. Suspicion falls on her scampish schoolmate (Leo Wan), but in reality she has been snatched away to North Korea. If she teaches a spy how to pass as Japanese, she’ll be released. Or so she’s told. The Great Wave illuminates a little-known episode in Cold War history — Hanako, we learn, isn’t the only abductee — while telling an unforgettable human story. It spans decades, the revolving set flipping us from interrogation room to family sitting room and back again. At home in Japan, Hanako’s mother (Rosalind Chao) haunts the sea shore, because she feels “closer to her there”. Her sister spends her time making missing-person posters, observing: “At least I get to see her face every day.” If you have tears, prepare to shed them now.