Sean and Leigh are in the scarab off of Maui investigating a new man-made reef that is being put in to lure additional tourists. Neither of them is happy with this new development because it has caused a shift in the rip patterns. Nick, a surfer, is also concerned and, for some reason, isn't feeling quite well. His brother Joe is surfing and tombstones. Sean and Leigh quickly jump into action and bring Joe to the beach. He is unconscious and Nick is nearly hysterical. Sean and Leigh try to get him to wait for the ambulance, but he's too caught up in trying to save his brother. The ambulance arrives and Nick hops in to go to the hospital.
In the hospital, Joe is fine but Nick turns out to have pneumonia. Sean and Leigh begin to suspect that there is something wrong with the materials that are being used to create the new reef. To complicate matters, Sam Parks has come back. Sean definitely does not trust Sam, and Leigh is loathe to tell him the truth about Sam's status as a Navy Intell