By Tom Gliatto Carrie Borzillo-Vrenna Bryan Alexander
August 28, 2006 12:00 PM

William Fichtner, most recently a human-alien-hybrid lawman on Invasion, is a sharp addition to the show as Alexander Mahone, the FBI agent and Dirty Harry look-alike on the convicts’ trail. But Patricia Wettig, so good in season 1 as the evil iguana-lady Vice President, is something of a lame duck: She’s busy with a new ABC series, Brothers & Sisters, produced by her husband, Ken Olin.