The third season opens three years after President Palmer's palm peril, with Jack Bauer back onboard at CTU for the latest L.A. crisis - a lethal virus. While taut situations define the series, what stands out in this commercial-free opener are the telltale tensions among the personalities. The president's impatient brother is his new chief of staff; a more mature Kim Bauer is a new CTU techie who has a strangely testy co-worker; and lone ranger Jack is now paired with an edgy new partner, Chase.