"Episode 16", also known as "Arbitrary Law", is the ninth episode of the second season of the American mystery television series Twin Peaks. The episode was written by series co-creator Mark Frost, producer Harley Peyton and regular writer Robert Engels, and directed by Tim Hunter. It features series regulars Kyle MacLachlan, Michael Ontkean, Ray Wise and Richard Beymer, and guest stars Miguel Ferrer as Albert Rosenfield, Don S. Davis as Major Briggs, and Al Strobel as MIKE.

Leland Palmer is a fictional character from the television series Twin Peaks, created by David Lynch and Mark Frost. He also appears in the prequel, Twin Peaks: Fire Walk with Me. He is portrayed in all his appearances by Ray Wise.