Horatio and his team must uncover the evidence in the brutal murder of an entire family in their own home. The only survivors are a blood-soaked toddler, and the father who is in surgery. The immediate assumption is that the mother is responsible—postpartum depression—but the evidence discloses a shocking, different outcome.

Horatio, Speedle and Calleigh root through the evidence in the homicide of a strange, unorthodox college professor when they find him tortured and hung onto a tree. Their suspicions are immediately directed towards his thirteen cult-like students. Elsewhere, Delko and Megan investigate a car found in the water with a dead body in the trunk, and immediately suspect an insurance scam.