Lily Tomlin Lily Tomlin

NCIS fans, your cries for more McGee stories have been heard.

The hit CBS procedural has cast four-time Emmy winner Lily Tomlin to play Penelope, the grandmother of Sean Murray's Agent Timothy McGee. She will appear early in the show's ninth season.

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"We know she'll bring extraordinary heart and pathos and humor to the show and the cast and crew are thrilled to have her," executive producer Gary Glasberg told Entertainment Weekly,

which first reported the news. "But don't let the word 'grandmother' fool you.  Penelope is sharp as a tack and we're about to learn some things about McGee's family that have never been revealed."Tomlin's television career spans four decades; her most recent small-screen work includes recurring roles on The West Wing, Desperate Housewives and Damages. She's currently appearing on Showtime's Web Therapy with Lisa Kudrow.

' ninth season premieres Tuesday, Sept. 20 at 8/7c on CBS.