Oak Point, Louisiana homicide detective Caleb Bourque is tasked with solving the case of a serial killer who leaves an unusual calling card with each victim -- a sprig of mistletoe. After Joanna Chatelaine, a co-founder of a women's outreach center, is killed, her sister Jamie starts receiving threats to her life if she doesn't close Magdalen House. Can Caleb unravel this complicated case before the killer makes good on his threat to kill Jamie?