Obsidian Knife is the second book in the series about Kate Fitzgerald—her life and work at Cahokia, a World Heritage archeological site in Southern Illinois.

She has been away for several years at graduate school and has now returned to take up a permanent position on staff—her ideal job. She has a friend (not quite a boyfriend), a mentor, a loving aunt as well as a great job. Her life was on a wonderful and exciting track until murder intervened. Not just any murder, but that of an important man in the volunteer support organization for Cahokia. A very public altercation at the society fundraiser the night before the killing leads to the general opinion that Kate’s friend, John, is the killer. When Kate steps in to try to prove John’s innocence, she finds that her job, her relationships and ultimately her life are put in jeopardy.