The subject of writing and receiving letters, which recurs frequently in the work of Johannes Vermeer (1632-1675), is given dramatic tension in this masterful painting of two women in a mysterious moment of crisis. The artist seldom, if ever, surpassed the subtly varied effects of light seen here as it gleams from the pearl jewellery, sparkles from the glass and silver objects on the table, and falls softly over the figures in their shadowy setting. The Frick Diptych series sparks a dialogue between creative spirits and art historians, promising new insights into some of the Frick's most famous masterpieces. The third volume, to be published in 2019, will have a contribution by author Edmund de Waal on a pair of porcelain and bronze candlesticks by the 18th-century French metalworker Pierre Gouthiere.