The Christmaswish, originally 'De Kerstwens', is a 2008 Samson and Gert special.
Samson and Gert are in the Ardennes to celebrate Christmas with their friends Modest, Eugène and Alberto. There, Gert discovers some stuff that belonged to his great-uncle Jan. Gert tells some amazing stories about Jan to his friends and he states that he hasn't seen his great-uncle in a while. He also says that he wants to celebrate one more Christmas with his great-uncle Jan.
Later on, Samson sees a falling star and wishes that Gert will see his great-uncle Jan soon. And the magic of Christmas seems to work, because Jan calls to say that he will come over to spend Christmas with Gert. Gert is now happier than he has ever been before. But soon afterwards, a winter storm comes up. This means that Jan won't catch his plane on time. Gert friends don't want him to be unhappy, so the mayor dresses himself up and pretends to be great-uncle Jan, but Gert doesn't believe it.
Via the radio, Gert finds out that Jan's plane is missing. Gert is now unhappier than he has ever been before. But only minutes later, great-uncle Jan enters the house, dressed up as Santa with a bag full of gifts in his hands.