Moominpappa At Sea by Tove Jansson (used.)

Moominpappa yearns to make a fresh start, to find a rocky island and lighthouse where he'll feel alert and important again. And so the Moomins set sail for a new home.

In Moominpappa at Sea they arrive at an island that proves as mysterious and wild as even Moominpappa had hoped. It even has a deserted lighthouse. But how is Moominmamma to grow her flowers and what strange fate befell the keeper of the lighthouse?