The machine spins freely when scattered lightning strikes on any of the golden lightning bolts on the fifth reel. The number of free spins you get ranges from 5 to 50. These free spin multipliers are determined by the number of golden lightning bolts obtained on the fifth reel when the reward is triggered.
In addition, if the No. 5 reel provides you with (one or more) red lightning and scattered golden lights, the machine will give you more free spins during any free spin.