Hi - I've reached the point where I've opened the inner sarcophagus but can't seem to get any further forward. The walkthrough says to go to the mural showing the blue cat and to brush the dirt from it but when I go there the mural isn't a hot spot and I can't do anything to it with the brush. I've spoken to Hotchkiss and Jon but it hasn't helped. I've obviously overlooked something but just don't know what. Any suggestions would be appreciated. Thanks