This quest is given by Clement and Sybille in the Bandit Camp.
If you mindread Christopher, you will find he is longing for some Rimmer's Rum, instead of the stale swill the bandits serve. If you ask Clement and Sybille about this, they only know that it is very rare. The Rum can be found if you continue into the camp — you will come across a wooden catwalk above the path. Climb the two ladders, and you will see two guards posted there: drunk Barney sitting on a stool, and sober Tagos. If you continue walking along the catwalk it will turn into a stone cliff ledge. At the very end, there is a crate and barrel hidden in a bush. The Rimmer's Rum is sitting directly in front of them.
While you can find the rum directly after picking up the quest, you still need to mindread Christopher in order to give it to him.
1500 XP and 400 gold are your base rewards, and one choice between some minor potion loot, a weapon, an additional 750 XP or 200 more gold.