Change is hard; and Carter (Colin Ferguson) is about to get more than he bargained for. Just as his life seems to be going smoothly, Zoe (Jordan Hinson) announces her acceptance into an early enrollment program for pre-med at Harvard. Neither Carter nor Lucas (Vanya Asher) saw that coming. Carter tries his best to appear thrilled for Zoe while Lucas buries himself in his work with Henry (Joe Morgan). While Carter is reeling from the news, new girlfriend Tess (Jaime Ray Newman) reveals that she?s contemplating a job offer that will start right after Allison returns - and it?s in Australia. Worse, she neglected to mention it before they slept together. Ouch. To top it all off, Henry and Lucas? analysis of the data downloaded from Kim reveals the approach of "Nemesis" - a neutron star that could reverse the earth?s poles and bring about the end of the world. Carter is somewhat relieved to learn that this event is about 2,000 years off.