Place 4 or 5 spindles on any reel and you will win 10x and 200x bets, respectively, and only 2 ingots will see your bet returned to you. Three or more scatter symbols will also take you to the free spin bonus round.
You can start this function by clicking on each ingot. Each will show some rotation - a number between 1 and 10. The total number of all ingots is the total number of rotations you have in this feature. The more scatter you use for the landing function, the higher the number may be.