Mystery Gone Wrong

Last night I lost my best friend. I came into school today hoping he was ok and would be here, but he wasn't. I was trying to hold back tears. I had just lost my two best friends to a murderer who I don't know the identity of. I only have 3 friends left to protect and I hope I won't fail. At lunch my friends Griff, Brigitta, and Axl came over to me. They obviously knew something was up because they immediately asked me what was wrong. There was no hiding this from them, they are my only friends that I have left and I want them to be safe. So I told them about everything, the list, the murderer, what happened at Luka's and what I saw at Andre's house. My friends understood that this was serious so they agreed to set traps up in their rooms to stay safe. Later that night I
decided to head back to Luka's house and see if the murderer had left anything behind. When I got there, I crept inside to look around. I called out "Hello, is anybody here?" and in a faint raspy voice someone said "Yes". I went to see who said that and saw Luka. But he seemed different. His skin had a more greenish tone to it. He turned around and I realized that he too had become a mutant zombie. Luka suddenly lunged at me so I ran out the door. As I was walking away from the house I heard Luka say "I'm sorry"