The subject of writing and receiving letters, which recurs frequently in Vermeer’s work, is given an exceptional sense of dramatic tension in this painting of two women arrested in some moment of mysterious crisis. The lack of final modeling in the mistress’ head and figure and the relatively plain background indicate that this late work by Vermeer was left unfinished. Nevertheless, the artist seldom if ever surpassed the subtly varied effects of light seen here as it gleams from the pearl jewelry, sparkles from the glass and silver objects on the table, and falls softly over the figures in their shadowy setting. Bought by Mr. Frick in 1919, the year of his death, this painting was his last purchase and joined Rembrandt’s "Self-Portrait," Holbein’s "Sir Thomas More," Bellini’s "St. Francis," and Velázquez’ "King Philip IV" among his favorite acquisitions.