The druid at the Great Tree wanted me to lead the zoo's anymals to him by means of Transport via Plants. I led all four of the zoo's anymals through the tree, and even massacred the zoo's guards and hunters, just to be sure. So i come back to the druid, and he...
...asks me if i need the key or the scroll again, and wether i'm still gonna do it. Dude, i just freaking DID. Or are you the kind of druid who won't notice when a bear, a wolf and two great cats all fall on your head through a tree? Huh?

So, tell, me, which one is being an idiot: me {stubbornly missing some obvious detail without which the quest cannot be considered complete}, the druid {see above}, or the game itself {a banal bug}? And - in eithr case - what is the solution?

Weird... you did both ask the animals to go to the courtyard, and then went to the courtyard and asked them to go through the portal? And you're sure that all the animals went to the courtyard (sometimes the AI mess up, and the animals will try to escape through the locked cage door and not the backdoor)?

I used empathy on them to bring them to the courtyard, and when all were there, asked them to enter the portal. Was i supposed to talk to them, instead of empathing them in the first place?