The military conscription of a beluga whale might sound like a conceit plucked from less-than-convincing spy fiction, but it is actually a well-documented practice. Since the 1960s, Russia and the United States have trained dolphins, seals and other marine mammals to assist their naval forces by tagging enemy divers, detecting mines and recovering items from the seafloor. Satellite photos of Russian naval bases near Murmansk, not far from the spot where Norwegian fishermen first found Hvaldimir, reveal the type of sea pens often used to hold belugas. Audun Rikardsen, a professor of marine biology at the Arctic University of Norway, told me that international contacts have since confirmed that Hvaldimir belonged to the navy.