Finding the Holotape
It's not as easy as it may sound, because there are no highlights suggesting what to do exactly.
You have to activate the skull that is on the library on the wall. The following screenshot shows the exact place:
In this way we activate the secret switch that moves the wall, behind which there is a room where we find the object we were looking for!
I will soon post a quick video about it, so subscribe to my Youtube and follow me on Facebook to receive all the updates!