Special Guest Stars Paul McGillion as Dr. Carson Beckett Amanda Tapping as Lt. Colonel Samantha Carter Guest Stars David Nykl as Dr. Radek Zelenka Kavan Smith as Major Lorne Mitch Pileggi as Col. Steven Caldwell Christopher Heyerdahl as Wraith Leader (Todd) Gary Jones as Sgt. Walter Harriman Michael Beach as Colonel Abe Ellis Martin Christopher as Major Marks Co Starring Chuck Campbell as Chuck Sharon Taylor as Amelia Banks Ben Cotton as Dr. Kavanagh Tyler McClendon as Wraith Colin Cunningham as Major Paul Davis