Hidden deep in a Russian forest, and guarded by soldiers with orders to shoot intruders on sight, the medical research laboratories on the outskirts of Moscow were one of the Soviet Union's best-kept secrets. So the carefully-vetted journalists who were allowed past the forbidding perimeter fence on a cold February morning in 1954 were both apprehensive and curious about what lay ahead. Led to a courtyard outside an austere brick building, they waited in the bright winter sunshine to find out why they had been summoned. For a few minutes, only the sound of birdsong and the rustling of leaves...