can't find trapdoor for Rotor

[feyone2]

Am in the hidden passage area and have killed Sepulchratos and am looking for Rotor but can't find him? have looked at grey stones along wall etc but nothing seems to activate. By the way am really having fun with the game!

[Indinera]

Am in the hidden passage area and have killed Sepulchratos and am looking for Rotor but can't find him? have looked at grey stones along wall etc but nothing seems to activate. By the way am really having fun with the game!

Glad to hear, just click on the cube in the middle of the room.
You must click not exactly on the middle of the cube, but just to its right.

[panna]

Am in the hidden passage area and have killed Sepulchratos and am looking for Rotor but can't find him? have looked at grey stones along wall etc but nothing seems to activate. By the way am really having fun with the game!

Glad to hear, just click on the cube in the middle of the room.
You must click not exactly on the middle of the cube, but just to its right.

I have killed Sepulchratos, am in the room with the grey stones along the wall. There are two large areas in the middle of the room. One a bit smaller that the other and slightly darker grey. I have been clicking all round them but nothing happens. I would not exactly call that a cube and certainly cannot go onto them. More like a wall. I cannot see anything else that resembles a cube. I can see the bottom bit on the left that would presumably open to Rotor. Where am I going wrong?
In the guide it says "check the middle grey cube in the last room". Which room?
Ok - I have finally found Rotor. The only way I did this was by going round "the cube" using keyboard not the mouse. Unfortunately, using the mouse to play the game is not necessarily accurate on finding "things".