Guest Stars Paul McGillion as Dr. Carson Beckett Craig Veroni as Dr. Peter Grodin Christopher Heyerdahl as Halling Ben Cotton as Dr. Kavanagh Fiona Hogan as Simpson Co Starring David Nykl as Dr. Radek Zelenka Boyan Vukelic as Sgt. Stackhouse Edmond Wong as Atlantis Technician Joseph May as Sgt. Markham