Set in 1660s London and in the early twenty-first century, this interwoven tale juxtaposes the worlds of of two women of remarkable intellect, Ester Velasquez, an emigrant from Amsterdam who is permitted to scribe for a blind rabbi just before the plague hits the city, and Helen Watt, an ailing historian with a love of Jewish history who has been summoned by a former student to view a cache of seventeenth-century Jewish documents and determine the identity of the documents' scribe, the elusive "Aleph."