Of all the radioactive elements discovered at the end of the 19th century, it was radium that became the focus of both public fascination and entrepreneurial zeal. Telling the curious, sometimes macabre story of the element through its ascendance as a desirable item, Lucy Jane Santos reveals that it was used as a present for a queen, a prize in a treasure hunt, and a glow-in- the-dark dance costume. In the 20th century, radium became a supposed cure-all, and Santos explains how medical practitioners and business people devised ingenious ways of persuading customers to welcome radioactive wares into their homes.