Moominhouse is filled with feverish activity, because everyone in Moominvalley has been invited to a fancy-dress ball in the old Manor, and attics and closets are savoured for suitable items. Fillyjonk has promised to introduce Snorkmainden to a young man of Family, and both she and Little My are beside themselves with excitement. Moomin is totally engrossed in a project of his own down by the river, a secret, nobody knows about until Snufkin happens by. This does not matter, but then Stinky finds out, and that is very serious, also coinciding with the ball, to which Moomin is supposed to accompany Snorkmaiden as Tarzan... (thetvdb.com)