Three quarters of a century ago, no one, not even the great Lord Rutherford (who discovered it), could describe the atomic nucleus. No theory was possible until it could be tamed experimentally and no satisfactory experiment seemed possible because it guarded its secrets so fiercely. And then, just at the point of despair, two young researchers at the Cavendish laboratory in Cambridge came along and, with paper-and-pencil calculations, hand-made apparatus and the occasional lump of plasticine, changed everything, egged on by Rutherford. This book tells the inspiring story behind the "miracle year" of British physics - 1932 - the atom was split, the neutron discovered and nuclear science born.