Dr. Samantha Hill (played by Kim Delaney) is a protagonist in 10.5.
Paul Hollister (played by Beau Bridges) is a protagonist in 10.5.
Roy Nolan (played by Fred Ward) appears in 10.5.
Dr. Owen Hunter (played by Dulé Hill) appears in 10.5.
Dr. Zack Nolan (played by Ivan Sergei) appears in 10.5.
Clark Williams (played by John Schneider) appears in 10.5.
Amanda Williams (played by Kaley Cuoco) appears in 10.5.
Carla Williams (played by Rebecca Jenkins) appears in 10.5.