My continuation of "The Fear" by Natasha Preston. Does Axel actually go through with murdering Izzy? What's next?

A weekend partying at a remote cabin is just what Mackenzie needs. She can't wait to let loose with her friends. But a crazy night of fun leaves two of them dead-murdered. With no signs of a forced entry or struggle, suspicion turns to the five survivors. Someone isn't telling the truth. And Mackenzie's first mistake? Assuming the killing is over...