Charlotte Holmes is back in a second adventure involving murder, family, and a decade-old cipher. Still employing the ruse of the "invalid brother," Sherlock Holmes, Charlotte finds herself investigating on behalf of the wife of the man she may possibly love while fielding a marriage proposal from that very man's brother. It will take all of Charlotte's sensible and analytical mind to see through her own surprising feelings as the web of Moriarty, and the involvement of a surprising member of her family, grows clearer.