The valley is having a festival with fireworks and fireflies, known as the Light Festival. It is held once every 142 years to commemorate a legend about how light was brought to the valley.
Buggle spots them, and they battle.
Moth claims this can't be so, since they were raised by Frank after their parents died, but King Boogieman explains that they were kidnapped by Frank, and that the parents thought Frank had killed them.
Enraged, Moth and Worm rebel against Frank, and completely ruin his plans. They then celebrate the festival with their parents.