The Avernum5Demo.dmg file you have requested: Official Demos / Avernum 5 Demo (Mac) - 27mb is not available. Perhaps try browsing all files for the game Avernum: The Great Trials Trilogy and upload any files you want to share or are missing. This is the only information we could locate:
The surface world is ruled by the Empire. Its power is absolute. Its control is unchallenged. And, as a soldier of the Empire, you have a good, comfortable life ahead of you. But then a rebel named Dorikas tried to assassinate the Empress, and everyt Spiderweb Software has released a playable demo of Avernum 5, allowing you to try out the Mac version of the latest game in the Avernum series due to ship in 2008.