Dream-Spice

The Dream Herb is a plant with really strange effects, growing at places where people had died. Eating it, the next time you go asleep, you will appear in the Dream World, as if you have entered it physically. However, the presence there isn't of substance.

The Avatar used it in Ultima Underworld II to enter the Shrine of Spirituality in the Dream World and remove one of the Blackrock Gems. Also, he/she gave some to Mokpo, so that he could flee into his dream land, giving some useful information in the process, how to get by some obstacles.