The Grinder alum Rob Lowe has joined the cast of CBS medical drama Code Black as a series regular. His character will be introduced in the Season 2 premiere on September 28. Lowe will play Col. Ethan Willis, a doctor in the U.S. military's prestigious Combat Casualty Care research program who has been pulled out of a combat hospital in Afghanistan and embedded at Angels Memorial to teach what the military has learned about combat medicine.