From 2006 to 2010, Walger had a recurring role as Penny Widmore in the ABC drama series, "Lost". She also had recurring roles on "Sleeper Cell", ', and '. In 2007, Walger appeared in the original Broadway production of "Frost/Nixon", as Charlotte Cushing, David Frost's then-girlfriend. Then she starred in the controversial HBO series "Tell Me You Love Me". The series gained notoriety even before the first episode had aired because of the frequency and extremely realistic nature of its sex scenes. Despite persistent rumours to the contrary, these scenes were eventually confirmed as simulated by several individuals intimately connected with the show. With reference to the manual masturbation apparently performed by Walger on actor Adam Scott at the end of the pilot episode, director Patricia Rozema and Walger's co-stars Ally Walker and Jane Alexander also explicitly denied that any actual sex took place on set. The series was canceled after a single season.