In August 1923, Mary Russell and husband Sherlock Holmes receive an unexpected visit from Dorothy Ruskin, an elderly amateur archeologist from the Holy Land, who met the couple four and a half years earlier during the events from O Jerusalem (novel).

As a gift, Ruskin presents Russell with an inlaid box containing a papyrus scroll, which seems to be a genuine first-century letter by Mary Magdalene.

A letter from her sister Mrs. Erica Rogers, who cares for their aged mother, reveals that two Middle Eastern visitors were also looking for Ruskin after her visit home.

Building the case, Holmes then persuades Russell to use the hypnotization techniques practiced on her as a child after her family’s death on one of the witnesses to Ruskin’s murder.

Russell recalls that Ruskin had complimented Holmes’s hands and his ability to solve puzzles, bringing both of them to realize the box she left them with may have a hidden compartment.