If you've already completed Illidan's Book of Heroes chapter, you might have noticed a rather strange pop-up screen after winning the last fight. For those who are yet to dive into it, we're talking about what you can see in the picture below.

Kerfluffle, Hearthstone Community Manager, published a post in Blizzard's forums uncovering the mystery. This pop-up is supposed to reward you with a Golden Standard Pack. Luckily, this will be retroactive so players that login to the game this week after the game patches with an update will receive their completion credit and won't miss out on the pack.

Quote From Kerfluffle

Separately, we’re aware of an issue where a pop up appears with placeholder text after finishing all Book of Heroes installments. We’ll be fixing this pop up in a patch next week and will be issuing a Golden Standard card pack to all players who completed Book of Heroes, which will be the reward for completing this content moving forward.

That does it for Hearthstone's Book of Heroes which made its debut just over 11 months ago. If Blizzard were to extend it or start a new book, which characters would you like to play the stories of? What did you think of Book of Heroes overall? Let us know in the comments below.