The life rune is an item used in the Gower Quest. It is obtained by flipping the pure essence found in a crate on Gower farm. It is needed to turn the Brassican amulet into the Cabbagespeak amulet. Life runes cannot be created using the Runecrafting skill. If asked about this after the quest, Andrew will say it's too dangerous and that it doesn't matter since no spells use life runes.