Dr. Jennifer Keller was originally Canadian, so Jewel Staite filmed her part with a Canadian flag on her sleeve. When it was decided there were already a lot of Canadian characters in the show, they used visual effects to replace it with an American flag.
Colonel Caldwell and the Daedalus were going to feature prominently in the story. As Mitch Pileggi was not available to reprise his role at the time, Colonel Ellis and the Apollo were introduced instead.
Jewel Staite appears for the first time as Dr. Jennifer Keller. She had previously played Ellia the Wraith in Instinct (2005).