Blizzard has added a new hero to Hearthstone - but you have to play World of Warcraft to unlock her.
Not only do you have to play WOW, you have to level up an entirely new character to the rank of 20 in order to bag Liadrin, the new Paladin hero option.
To be clear, this is not a new class in the game. Liadrin is simply a different Paladin option, with fresh hero animations and taunts.
Anyone reaching level 20 in WOW with a fresh character will find Liadrin available in their Hearthstone account.
If you don't play WOW, you can reach level 20 with the free Starter Edition. But you still need around three hours to get through the game's early areas and level up enough.
Blizzard has linked rewards in its various games before, although this is by far the most demanding requirement yet. Usually, unlockables are awarded for simply owning other Blizzard titles.
For WOW veterans, is this the moment you try out a new class? Is this the moment I play WOW for the first time?
To stay on top of all the latest Hearthstone developments, take a look through our dedicated Hearthstone site MetaBomb.