It was, not so original and I did not liked it - first it might have looked exciting but on one point, when it was understandable what is going on, it lost all it's beauty. Not that it was very similar to "Tin man" and they did not offered nothing new - quite filler episode.
Only thing I liked was the end - the garden was so beautiful and the Keeper, so worried that everything will be ruined. And the idea of showing some events from the past - and show that whatever they would have done, they would not succeed. But it was not enough to make this episode feel better.