Pingu and the Message in a Bottle is the tenth episode of the third season.
When Pingu arrives at the lake to join for a day of fishing with Pingo, they notice a bottle floating on the service of the water. Pingu throws a snowball at the bottle to make it float towards the bank. After the bottle has been fished out of the water, Pingu breaks it open to find it contains a map leading to a buried treasure not far away.
Using the map, Pingu and Pingo set off to find the treasure. The trail takes them across the narrow ridge of a cliff. They most try not slip off the walk way, keep an eye out for the falling lumps of snow and make sure that the weaker parts of the ridge do not give way under their weight. At the end of the cliff, it slopes down towards an abandoned igloo with a boarded-up entrance. The treasure should be just behind the boards, so they slide down to the bottom of the slope and Pingu removes one of the boards blocking up the entrance of the igloo. He crawls inside and soon reappears with a wooden treasure chest. Without a key to unlock it, Pingu prises off the pad lock with a steel rod and he and Pingo lift the lid to find only a large oyster. Pingu and Pingo are slightly disapointed that there is nothing more to the treasure, but at least the box will be useful for storage. After a small debate about who needs it more, Pingo takes the empty wooden chest and lets Pingu take the oyster as a present for his mother. Pingu and Pingo then return to the lake where they pack away the fishing gear and set off for home.
Back home, Pinga is very eager to play with Pingu's oyster, but is not too happy when Pingu tells her it is for Mum. As Pingu presents Mum with the oyster, Pinga researches up very suddenly to grab it. Mum is so taken by surprise that she drops the oyster on the floor. The impact causes the oyster to come open and a small white pearl rolls out in front of them. Pingu is delighted; it seems that there really was a treasure after all and he has it. Pingu feels very lucky indeed.