I found a keg containing wine with magical properties.
Talk to Darva
I drank the wine until I blacked out and woke up in Riften. I should talk to Darva to find out what happened.
Talk to Innarrek
Darva mentioned that Riften's housecarl Innarrek wishes to speak with me after my drunken escapade.
— game journal
Note: This wine was intended for the bandits, so they would be cursed. One not necessarily does have to drink it.