The Stingray crew investigates after a decommissioned lighthouse mysteriously reactivates, and causes a confused pilot to crash his aircraft.
Frank Lincoln, the keeper of the Arago Rock Lighthouse for forty years, shuts down the light for the last time. A new airbase was built on Arago Point, and the light would confuse pilots as they came in to land. Admiral Frendor dedicates the lighthouse as a historic landmark, and the Marineville staff decide to throw Frank a party to celebrate his retirement and years of service.
As Frank returns to shore in his dinghy after shutting off the light, a pilot comes in to land a plane at the new airbase. Suddenly, the light mysteriously comes back on, confusing the pilot and causing him to crash.
Marineville is unable to reach the lighthouse via radio. Frank returns to the lighthouse to investigate, but is captured by a mysterious underwater race. When there is no answer from Frank, Shore sends Stingray to investigate. Troy and Phones find Frank's dinghy, but no trace of Frank, so Troy leaves Stingray to enter the lighthouse.
When Troy doesn't respond after being captured by the same pair who captured Frank, Phones goes in after him, leaving Marina in Stingray. Phones is also captured by the pair, who take him to where they are holding Troy and Frank. They introduce themselves as Lorif and Cromer, and explain that the light from the lighthouse causes the local sea anemones to open and close. Their people have harnessed the movement of the anemones-small generators attached to each flower create energy to power and heat their city, called Prisma. If the light were to go out, their power source would cease to exist and their civilization would die within a week.
A worried Marina is still in the submarine, and contacts Marineville, who dispatches Rescue Launch 8. Troy convinces Lorif and Cromer that WASP will replace the light for the lighthouse, and they accept his offer. Frank is sent up to Stingray to flash the floodlights. However, Marina doesn't know who he is and refuses to let him on the sub. Eventually, he convinces her that Troy sent him, but he and Marina don't know which control operates the lights.
In a race against time, as Troy and Phones will be killed if the lights are not turned on, they managed to find the right controls and flash the floodlights. Lorif and Cromer let Troy and Phones go, and they quickly escape, though they feel bad about leaving since without the light, the city underneath the water around the lighthouse is doomed.
Frank is awarded a medal for his years of service, and is given a job overseeing the signal lights at the Tracking Station. Frank is flattered but expressed regret that the Prisma is doomed. Troy reassures him that the WASP engineers are working to fix the problem, and will develop something to replace the lighthouse.
The next day, Stingray takes out a "Submarine Beacon" that is placed on the ocean floor. It's flashing light will provide light to the anemones and power to the city, and since it is underwater, will not confuse the overflying pilots. Power is restored to Prisma, and the inhabitants express their gratitude to the crew of Stingray.
Regular Voice Cast
- Captain Troy Tempest - Don Mason
- Lieutenant Phones Sheridan - Robert Easton
- Lieutenant Atlanta Shore - Lois Maxwell
- Commander Sam Shore - Ray Barrett
- Sub-Lieutenant John Fisher - Ray Barrett
Guest Voice Cast
- Frank Lincoln - David Graham
- Admiral Frendor - David Graham
- Cromer - David Graham
- Lorif - David Graham
- Sky Eagle 127 Pilot - Don Mason
- Arago Point Air Base - Lois Maxwell
- Rescue Launch 8 - David Graham
WASP Equipment Used