Constance Zimmer joins GREY'S ANATOMY
Zimmer will play Dr. Cahill, a confident, self-possessed and laser-focused doc with a wicked sense of humor.
TRUE BLOOD's Janina Gavankar joins ARROW
Gavankar will play McKenna Hall, a vice cop with the Starling City Police Department. Tough, sexy, and considerably formidable, McKenna has a complicated history with Oliver (Stephen Amell).
