Unfortunately for the Champions, they've stumbled into Undermountain, the dungeon of the mad mage Halaster Blackcloak...
Note: you will need to have completed the previous two Dragon Heist Adventures, Nimble Escape and Fugitives, in order to access these new Adventures.

Hopelessly Lost
After following their quarry into Waterdeep's sewers, the Champions have become lost in Undermountain. It's going to take everything they have to try and find their way back out again!- Variant: Bazaar Exploits — Two Goblins accompany the Champions, taking up spots in the formation. Every 25 Areas the two Goblins change their location. While attacking Xanathar Guild enemies, Champions' damage is increased.
Enter the Sargauth
The Champions are on the hunt, looking for a way to Skullport - after all, they have a stone to find - but something else is already on the hunt for them...- Variant: Elder Rune Madness — Each time you enter the portal, a different Elder Rune takes effect for the next 50 Areas. These Elder Runes vary in effects from Champions taking damage whenever monsters spawn to random debuffs, monsters dropping less gold, and Champions being unable to regain hit points or gain shields. Good luck!
See the in-game Change Log for more information!