Jasper was a talented wizard who specialized in the making of potions. He was also the uncle of the famous Een hero, Juniper Jinx. He was known for his kindness and gentle wisdom. In all likelihood, he would have served in the council of Winter Woodsong, except that he disappeared beyond the magic curtain.
It happened during an expedition that Jasper and his niece took to the Forests of Wretch, in the world beyond the magic curtain of Een. The two hoppers were attacked by Goojuns, and were separated. Amidst the chaos, Jasper dropped his pouch of potions. This turned out to be good luck for his niece, who found the pouch and was able to use a strength potion to save herself from the Goojuns.
As for Jasper, no trace could be found of him and it wasn't longer afterwards that Eens stopped venturing beyond the magic curtain—at least until the Box of Whispers was stolen.