One sunny afternoon, the Mystery Machine was driving along a coastal road. Inside, Fred was at the wheel, with Velma, Daphne, Shaggy and Scooby-Doo as his passengers. They were on their way to visit their friend, the lighthouse keeper.

As they neared the lighthouse, a dense fog rolled in. The lighthouse towered ominously in the gloom, its light flickering intermittently. The gang exchanged nervous glances.

They were greeted by their friend, Mr. Jenkins, the lighthouse keeper. He appeared worried and explained that strange things had been happening at the lighthouse recently.

Mr. Jenkins told them that the lighthouse's light would flicker and go out at night, despite being in perfect working order. He also heard eerie whispers and footsteps when no one else was around.

Intrigued by the mystery, Fred decided that they would investigate the haunted lighthouse. Velma, Daphne, and Fred would explore inside while Shaggy and Scooby kept watch outside.

Inside the lighthouse, the trio found old maritime artifacts and maps. They also noticed strange scratches on the floor, as if something heavy had been dragged across it.

Outside, Shaggy and Scooby were huddled together, shaking with fear. Suddenly, they heard a whispering sound and saw a shadowy figure moving towards the lighthouse. They screamed and ran inside.

Hearing the commotion, Fred, Velma, and Daphne rushed to the entrance. They saw Shaggy and Scooby pointing towards the foggy outside, babbling about a ghostly figure.

The gang decided to stick together and investigate the figure. They ventured into the fog, with Scooby and Shaggy reluctantly leading the way. The eerie whispers grew louder as they approached the figure.

As they neared the figure, they realized it was just an old weather vane blowing in the wind. Relieved, they laughed and returned to the lighthouse.

Back inside, they continued their investigation. Velma found an old diary that belonged to the first lighthouse keeper. It mentioned a hidden treasure in the lighthouse.

The gang realized that the strange occurrences could be related to the hidden treasure. They decided to search the lighthouse from top to bottom.

They split up again to cover more ground. Fred and Daphne went upstairs to the lantern room, while Velma, Shaggy, and Scooby searched the ground floor.

In the lantern room, Fred and Daphne found a secret compartment in the wall. Inside, they discovered an old, dusty treasure chest.

Downstairs, Velma noticed that the scratches on the floor led to a trapdoor. She, Shaggy, and Scooby opened it to reveal a secret tunnel.

The gang regrouped and decided to explore the tunnel. Armed with flashlights, they ventured into the darkness, with Scooby leading the way.

They followed the tunnel until they reached a hidden room filled with old pirate artifacts. There, they found another treasure chest, identical to the one found earlier.

Suddenly, they heard the eerie whispers again. They turned to see a ghostly figure in a pirate costume. It warned them to leave the treasure and disappear.

Shaggy and Scooby screamed and ran away, followed by the rest of the gang. They managed to escape the tunnel and returned to the lighthouse, shaken but safe.

Despite their fear, the gang decided to unmask the ghost. They set a trap for the ghost using the treasure chests as bait.

As expected, the ghost appeared to claim the treasure. The trap was sprung, and the ghost was caught. The gang approached cautiously to unmask the ghost.

The ghost turned out to be Mr. Jenkins. He had discovered the treasure and was trying to scare everyone away so he could keep it all for himself.

Mr. Jenkins was handed over to the police, and the treasure was donated to the local museum. The lighthouse was no longer haunted, and the light shone brightly again.

The gang celebrated their victory with a feast in the Mystery Machine. Scooby and Shaggy devoured their sandwiches, while the others laughed and recounted their adventure.

As they drove away from the lighthouse, they felt a sense of satisfaction. Another mystery had been solved, and they were already looking forward to their next adventure.