On November 12, 2007 Spiderweb Software released Avernum 5 for Macintosh, followed by the Windows version on February 16, 2008. The game utilizes the same game engine as its predecessor, but differs greatly in its plot element. Instead of being hired by Avernum (as with all other chapters in the series), the party of adventurers in the story fulfill the bidding of the Empire. The player controlling the party must hunt down the assassin Dorikas while dealing with numerous other obstacles such as spies and betrayal. Meanwhile, characters in the party are trained in over fifty spells and battle disciplines. Battle disciplines are applied on an axonometric game grid sharing an interface with Avernum 4.