
The player is later tasked with venturing into Na-Krul's lair and vanquishing it. A sorcerer, while performing a ritual, unknowingly releases the demon Na-Krul unto the town of Tristram, but before it can completely escape, the sorcerer magically seals the doors.

Hellfire's storyline occurs as an aside to the main story arc of the original game. However, the expansion does offer many new features as a single-player game, and also does not interfere with a user's ability to still play Diablo with Blizzard's service. While there are some multi-player modes that can be unlocked, Hellfire is not playable on Blizzard's online gaming service, and its changes do not transfer to online characters. Hellfire is a single-player expansion to Diablo.

The original game was later re-released alongside Hellfire in 1998 in a bundle called Diablo + Hellfire. Blizzard Entertainment has never released a first-party expansion for Diablo.

Hellfire is the only authorized expansion pack released for Diablo. It was released in 1997 and developed by Synergistic Software, a Sierra division. Diablo Hellfire Download Free Full Game is an expansion pack that Sierra On-Line produced for the video game Diablo.
