Hearthstone's next expansion has a hell of a twist.

Kobolds & Catacombs will add a total of 135 new cards to the game, including brand-new legendary weapons for all nine classes, an adventurer named Marin the Fox, and a bunch of crazy cards like Tolin's Goblet, which lets you draw a card and then fill your hand with copies of it.

There's also a new keyword, "recruit", which summons a random minion from your deck.

But the real surprise is the completely separate single-player mode in Kobolds & Catacombs, called Dungeon Run.

A rogue-like dungeon crawler, Dungeon Run challenges you to defeat eight random bosses chosen randomly from a huge pool of 48 possible encounters.

At BlizzCon, Matt sat down with Hearthstone production director & VP Jason Chayes and technical director Steve Shimizu to talk about D&D modules, the state of Hearthstone's meta, and more.