Cold Case's Kathryn Morris has just joined the high school drama The Sophomore. According to The Hollywood Reporter, she will play Nurse Platt, a vegan/hippie stoner high school nurse.

In this teenage take on Chinatown, Mischa Barton plays the most popular girl in her Catholic high school. She persuades a sophomore reporter (Thompson) to investigate the theft of SAT exams, but after he reveals that the school's president and top jock are responsible, a more sinister conspiracy emerges.

Rumer Willis plays the troublemaking sidekick of Barton's character. Bruce Willis plays the school's twisted principal, a Desert Storm veteran who can't let go of his glory days in Kuwait.

The Sophomore opens April 25th, 2008.