While on the North Star, Ben discovers a strange device in the water that could lead to Chris.
Old friends return to Bristol Cove. Ben investigates some suspicious overfishing. Decker ramps up his efforts to find his escaped mermaid and shows the true extent of his influence.
When the military facility is on high alert, Chris escapes along with a traumatized "nurse."
Ben and Xander abscond with the North Star to catch their own mermaid but things don't go as planned.
Bristol Cove mourns a loss causing Ryn to become more human and showing the distance between Ben and his father.
