'They can't have moved away without saying a word!'
Winter is coming, and the Fillyjonk, the Hemulen, Toft, Mymble, etc. are all waiting in Moominvalley to see the Moomins return home. Winter doesn't seem right without them . . .
Moominvalley in November (1971) by Tove Jansson, the eighth book about the Moomins, winds up the series, as six friends of Moominpappa and Moominmamma travel separately to their home, only to find that the Finn family Moomintroll is gone. The lonely Snufkin, Fillyjonk, Toft and the others eventually find the companionship they're seeking in each other.