You are helping some librarians to find a very old book. Upon finding it, you discover that there is a secret door leading to another dimension where a demon resides that, if no one cures it, will escape and wipe out all of humanity.
To get in you need some magic symbols that open the door and a secret weapon that can kill the demon.

You will have to travel to Italy (Rome), Greece (Crete, Sparta and Athens) and Spain (Atapuerca, in Burgos) and pass a series of tests that will allow you to get everything you need to end the demini.