His feet, or more accurately, his boots.

Jack looked around at all of his body parts and the first ones to start moving were his feet. But due to him wearing his favourite red leather boots, he thought that his boots were the ones moving. "Hey feet, come 'ere!" he called to them and his feet walked casually over to his head. "Umm...do you know what just hit us?" he asked them. His boots stood on their heels and shook left and right as if they were saying no. "How curious..." Jack's head thought. "Hmm..." he didn't really want to hop around so he asked his feet another question. "Do you think I could attach to you and use you to move around?"

The boots tapped their toe parts and fell backwards as his bare feet shuffled out. Jack head hopped over to them and jumped on top. Now, being able to control his feet, he looked down at them and wiggled his toes. "Right then...let's get everyone else rounded up..." he said as he walked over to his arms, who were scuttling around using his hands. "Huh?" he wondered as he pushed his glasses up with his big toe, "What are my arms doing?" he walked over to them. "Hello arms, something bothering you?"

His arms were quite surprised to see the head as they hugged him in relief. They thought he had got blown away during the explosion. "Yes, yes, I'm happy to see you too..." he muttered. His arms put him back down. "Arms...and hands, do you know what that bright light was that hit us from the sky?"

Jokingly, his hands pointed to the sun. "No...it couldn't have been the sun...that produces heat, not a powerful and explosive **** that could tear a person apart limb from limb..." Jack's head replied. Strangely, no matter which body part he spoke to, they all had the same answer...they didn't know.

"Hmm...there's only one character in this story who might know what hit us..." he thought. "Hey N." Huh? What is it, Jack? "N, do you know what hit us?" Umm...well, I did say in the introduction that it was some kind of bright light that came from the sky...that's all I know. "Hmm..." Hmm indeed... "Hey...I know...why don't you ask the only other OTHER one that might know!" Who would that be? "The reader! Because like you explained to me, whatever option they pick would affect the story!"

You're right! Let's see what they know of this light...