Little Mys older sister, Mymble, comes to Moominvalley. At the same time two tiny creatures come there too, Thingumy and Bob, with a giant suitcase that they protect. Though they are not the only visitors, The Groke is not far behind.
Too-Ticky brings Ninny to Moominhouse. Ninny has been frightened so often by her aunt that she has become invisible. Moominmamma concocts an infallible remedy, but will that and kindness be enough? Stinky does his best to see to it that it doesn't.
Moomin and Little My is still awake after awakening from their hibernation. And they get to meet the inhabitants who visits Moominvalley during the winter.
Moomin and friends have a great time in the jungle. Suspiciously helpful, Stinky offers to get them some animals, too, so it will be more like a real jungle. He is as good as his word, but the animals that he provides are not exactly of the kind they had in mind.
Moominfamily has already started hibernating when they are woken up by a busy Hemulen, who tells them they can't possibly go on sleeping when Christmas is coming!