Unravelling the Double Helix covers the most colourful period in the history of DNA, from the discovery of 'nuclein' in the late 1860s to the publication of Watson's The Double Helix in 1968. This is a saga packed with awful mistakes as well as brilliant science, with a wonderful cast of heroes and villains. Surprisingly, much of it is unfamiliar, because the early history is largely neglected by books which focus on the episode of the double helix. The elucidation of the double helix was one of the most brilliant gems of twentieth-century science, but Gareth Williams shows that to ignore everything that went before is as irrational as prising the biggest diamond out of the Coronation Sceptre and turning your back on the rest of the Crown Jewels.