She was a goddess of truth and justice, and also the personification of them. Maat carries an ostrich feather, which resembles truth. 
Three things refer to Maat in The Last Revelation:
- A puzzle in the level Temple of Horus. On the scale there are a silver pitcher and a feather, the feather being a symbol for Maat.
- The demoness from the Egyptian netherworld, which will be encountred in the level Temple of Horus, if one fails the Scales Riddle.
- Wikipedia article on Maat Retrieved on 31st of Dec 2012