I typed "the cat turns back" but that was marked wrong. I read someone on here ... think it was "mads-lime", explaining in another discussion that "at vende tilbage" means "turn back", and "at kommer tilbage" means "go home". Which is why I wrote "turns back". I don't think he's wrong as he seems to be a native speaker to me. Hope someone can explain more.
On the subject of some of the new verbs introduced in this lesson, I understood that "returnerer" means to return an item or an object, not "return home" or "return" to some place.