
The expansion pack adds several enhancements to Diablo, including an additional Monk class, two new dungeon settings – namely The Festering Nest and the Demon Crypts – additional quests to undertake, several extra game items – including oils which affect item statistics and runes that can be placed as traps – a new page of spells, new affixes for weapons and armor, new shrines, new mini-boss enemy names, a noticeable boost to Diablo's strength and power, and a number of interface improvements. The player is later tasked with venturing into Na-Krul's lair and vanquishing it. A Sorcerer, while performing a ritual, inadvertently unleashes the demon Na-Krul upon the town of Tristram, but before it can completely escape, the Sorcerer magically seals the doors. Hellfire's storyline occurs in parallel to the main story arc of the original game.
