In the 1940s, Sweden was rocked by a scandal when it emerged that two mothers had had their children swapped at the maternity clinic in Bureå, Västerbotten, and had raised them as their own. By the time the tragedy came to light, the children were three years old; as they approached the age of seven, the Supreme Court ruled that the boys should be returned to their biological families. One of the boys was a cousin of the author P.O. Enquist, and the incident—which left a profound mark on him—is a subject he has revisited several times, most notably in his novel *Captain Nemo’s Library*. In this documentary, P.O. Enquist and his relatives share how the mix-up affected their lives. We also learn the backstory of the event, which would reveal a secret far greater than anyone could have imagined.