With the Sirens at the top of the charts, Mike has turned into a self-centered celebrity. His friends worry for him and Allie grieves the wonderful man she had loved for seven years. In an effort to save Mike from himself his friends propose a mission: find out why the earth was so sparsely populated when the Dandelions invaded New Durham. Once again, the teams discover that time travel messes with your mind. Back in the present, a series of tragedies only serve to make Mike more obnoxious, forcing Allie into a fateful decision. She has to leave him.