In Black Diamond, Holtzer has created a deeper, more complex work that retains and further enriches the characters of her protagonists, computer maven Anneke Haagen and her lover, police lieutenant Karl Genesko. It also brings back the enchanting student Zoe Kaplan, the Michigan Daily reporter who was introduced in Holtzer's last book, Bleeding Maize and Blue. Zoe is enlisted by a hapless fellow student for moral support in her family's dissension over a will. In the process, the two young women come upon an intriguing series of letters written by the student's ancestor (a well-born lady brutally treated by her logging-baron husband) and a barely literate prostitute (a camp follower of the logging crews), who find a common chord in their unhappy lives. By unraveling the correspondence, with the help of computer-knowledgeable Anneke, the two students unearth a tale of arson, murder, and lost treasure that reaches out to touch their own lives.