The 5th clue you get by talking to the Dragon Statue close to the 5 runes on the wall. The statue wants you to chose the correct combination of Cat, Totem and Maxos. If you talk to Valeri(?), he will tell you what the different runes on the wall stand for (Cat, Totem and Maxos).
The combination is Cat, Totem, Totem, Maxos, Cat.
Down there you get a clue relating to Maxos.
