Ryan is forced to interfere with an autopsy as Helen gets closer to the truth. Philip deals with a surprise visit from his mom, and Lukas struggles with anxiety about the cabin murders.

Eyewitness delves into the lives of Philip and Lukas, two innocent teenage boys who bear witness to a triple-homicide while in the midst of a romantic encounter. Desperate to keep their relationship a secret they must keep what they've seen hidden from everyone, including Philip's new foster mother, Helen, a former big-city homicide detective who left her harrowing career to become a small-town sheriff. With a murderer on the loose who is desperate to silence any link to the killings, Helen will stop at nothing to solve the case and bring peace back to Tivoli.