The Forbidden Evergreen

No one knew what was behind the door that held the secrets of centuries, but all they knew was that they couldn't enter, at least not without returning that is.
There has always been a saying, that curiosity killed the cat but satisfaction brought it back. In my case that was slightly different.
Curiosity did kill the cat, however, there was nothing that would bring back that cat, not after entering through the forbidden evergreen.
That is how I ended up in the situation, curiosity was running deep, of opening the forbidden door, and entering.
To not be found, or heard from ever again. Let's see what brought the overwhelming curiosity that killed the cat.