This stage requires two shots to obtain the three star mastery. Aim your first pig at the first metal tower.
Power Activation Point
Activate the power to let the lightning strike hit the metal. The electricity travel through the metal chain, killing the birds in the second tower.
First Shot Result
With the second tower cleared, now you have a clear shot to get rid of the bird in the third tower. Aim at the metal part of what is left over.
Second Power Activation Point
Activate the power so that your lightning bolt strikes the metal part.
Second Shot Result
The electricity travels through the metal chain, killing the bird in the last tower.