Hearthstone: The Witchwood expansion will have a Dungeon Run-style 'Monster Hunt' mode

A trio of Hearthstone developers went into the forest to discover the secrets of The Witchwood, the new expansion for Hearthstone. They were never heard from again—but we did get a pretty cool teaser out of it.

Set in the Worgen-cursed city of Gilneas, the Witchwood expansion will feature 135 new cards, a few of them found conveniently hanging in a tree by Hearthstone head guy Ben Brode. Azalina Soulthief will replace your hand with an exact copy of your opponent's, which should lead to some interesting strategic back-and forth; there's also Genn Greymane, a neutral minion who will reduce your starting Hero Power cost to just 1 if your deck has only even-cost cards at the beginning of the match, and Baku the Mooneater, who will upgrade your Hero Power if your deck contains only odd-cost cards.

There's also a new Echo keyword that enables a card to be played multiple times on the same turns, and Rush, which can attack minions the same turn that they come into play—similar to the Charge keyword, except it's only against minions. Worgen cards swap attack and health each turn they're in your hand, so you can hold onto them at different times for different results.

The video wraps up with a tease for a Hagatha card—a new hero card, quite possibly, but there appear to be at least a couple of Hagathas in the WoW mythos—Hagatha Moorehead, Matron Hagatha—and neither of them look like the character on the card. The only thing we can say for sure at this point is that it's apparently OP as hell. Blizzard has to hold something back, after all.

The expansion will also add a new Monster Hunt mode to the action, similar to Kobolds & Catacombs' Dungeon Run, that challenges players with a series of eight increasingly difficult encounters leading into a big boss fight. And there will be four new heroes to lead the fight, each with their own hero power and "cards that create completely new playstyles and strategies."

Hearthstone: The Witchwood is available for pre-purchase now, with a bonus 20 packs and "In a Dark Wood" card back on the table for people who pony up early. Witchwood card reveals will begin on March 26, and the expansion is slated to go live in mid-April. We will no doubt have a more detailed analysis of the new cards as they become available, but for now you can get a closer look at what's cooking at thewitchwood.com.

Oh, and I'm pretty sure those Hearthstone guys in the video are actually perfectly OK, so you can stop worrying about them and have a look at the first of the new cards down below.