Stuart Roberts writes: “Two notebooks belonging to Charles Darwin, one of which contains his iconic 1837 ‘Tree of Life’ sketch, have been safely returned to Cambridge University Library, more than two decades after first being reported missing. The notebooks are in good condition, with no obvious signs of significant handling or damage sustained in the years since their disappearance. They were returned in a bright pink gift bag containing the notebooks’ archive box and inside a plain brown envelope addressed to the University Librarian with the printed message: ‘Librarian/ Happy Easter/ X.”