Talk to Wizard Mizgog, who is located on the third floor of the Wizard's Tower south of Draynor Village.
Ask him for a quest, and he will tell you that another wizard has set an army of imps against him. They have supposedly stolen his items, including his magical-coloured beads. He will ask you if you can retrieve them for him.
You can either buy the beads from the Grand Exchange or other players, or you can kill imps for them. Imps can be found all over the lands of RuneScape, but a good place to find them is near Karajma volcano. You will need to get red, yellow, black and white beads.
Once you have collected the four beads, take them back to Mizgog.
Congratulations! Quest Complete!
Guide Made by: Flame
Corrections submitted by: DaDa, Yolk, Jamie, Runis Altair, Marc J, Dx1438, Panda, Rebecca, Secepatnya, Sytze