“It’s a Wonderful Death” – When Allison’s brain tumor resurfaces, its aftermath could have life-altering consequences for her friends and family, on the sixth season finale of MEDIUM, Friday, May 21 (9:00-10:00 PM, ET/PT) on the CBS Television Network. Guest stars include Teri Polo (“The West Wing”) as murder victim Mary-Louise Graff and Margaret Colin (“Gossip Girl”) as D.A. Kelly Shuler. Photo: Sonja Flemming/CBS ©2010 CBS Broadcasting Inc. All Rights Reserved.