NCIS: Los Angeles: Executive producer Shane Brennan says the September 20 premiere includes a flashback to "Callen with his never-before-seen mother in a location we've seen before." Brennan pre-shot a scene last year with Chris O'Donnell's son, Finley, 5, as little Callen. "My son didn't know what was going on at the time and neither did I," admits Chris. "Not until I read the season-premiere script did I realize what Shane had done. It's pretty amazing."