Suspicious symptoms afflicting a group of children on the coast may be linked to the death of a local man.

Leo hunts for the source of the children's symptoms before any more fatalities occur. Meanwhile Harry discovers the truth behind Nick Garner's death.

Nikki and Harry try to help wounded victims of a campus shooting while trapped in the building with the rampaging shooter.

Leo's postmortem of the victims reveals there were two guns used, and possibly a second shooter.