Some of you asked about how to open certain doors in the Library. C'mon, it's just a simple brain-teaser! (and a tutorial before the following levels) All you need is to find your way behind the first door and open it from a distance. Then find another by-pass route through a breakable door and another hole in a wall. Then find a way to open the locked door. Draw your attention to lustres.
![](https://i.ytimg.com/vi/TxgyssdVPqs/maxresdefault.jpg)