In the summer of 1941, German troops surrounded the Russian city of Leningrad – now St Petersburg – and began the longest blockade in recorded history. By the most conservative estimates, the siege would claim the lives of three-quarters of a million people. Most died of starvation. At the centre of the embattled city stood a converted palace that housed the greatest living plant library ever amassed – the world’s first seed bank. After attempts to evacuate the collection failed, and as supplies dwindled, the scientists responsible faced a terrible decision: should they distribute the specimens to the starving population, or preserve them in the hope that they held the key to ending global famine?
