Can You Keep a Secret?

Prologue

"I can't believe you talked me into going camping with you." Allison huffed as we trudged up the hill.
"We needed a vacation away from everyone, and camping in the forest doesn't cost any money." I replied. "Besides, it's only for a few days."
We walked for another ten minutes and came to a clearing with a tree in the center.
"This should do," I said. "It's almost dark, so it's not like we have a choice."
"Works for me. I don't think I could've walked much further any ways."
As much as I love my best friend, Allison, she complains, and talks a lot.
"Let's just get the tent set up, so we can get away from the bugs." I respond.
"Katherine?"
"Hmm?"
"Is something wrong?"
"No, just exhausted."
"Oh, well you need to stay a little longer. Since we're all the way out in the middle of nowhere, we may as well see the full moon."
"That's tonight?" I asked.
"Yep," Allison said as we finished setting up the tent.
"Ok, but after all our stuff is put away and we see the moon, I am going to bed."
"You know you complain a lot," Allison said.
"Not nearly as much as you." I open the tent and unroll my sleeping bag. I set the rest of my stuff at the foot of my sleeping bag and sat on the grass. "You're right, the moon is pretty big."
"What is that?"
"What do you... mean?" I say as I turn around to see what Allison was talking about.
The tree in the center of the clearing was glowing. I slowly walked towards it.
"Are you kidding? Don't go towards the light! This is how people die in the movies!" Allison shrieked.
"Aren't you the least bit curious?"
"Uhhh! Kill me now."
Allison and I approached the tree. the rough bark was glowing a light purple. The glow began pulsing as we got closer and the shade turned darker and darker. We reached our hands out and touched the tree. A shock ran through my body as I pulled my hand away.
"What the..." Allison started.
"The tree, it stopped glowing." I turned to face Allison. "You're eyes! They're purple!"
"So are yours!" Allison gasped.
"What have we done?"