Highlights from the Third Episode of Season 9 of NCIS

The line between McGee's personal and professional life is blurred when NCIS uncovers a connection between his grandmother and the murder of a Navy lieutenant. Lily Tomlin guest stars as Penelope Langston, McGee's grandmother. Pictured left to right: Lily Tomlin, Sean Murray and Michael Weatherly

Lily Tomlin guest stars as Penelope Langston, McGee's grandmother. Pictured left to right: Sean Murray, Lily Tomlin and Michael Weatherly

The line between McGee's personal and professional life is blurred when NCIS uncovers a connection between his grandmother and the murder of a Navy lieutenant

The line between McGee's personal and professional life is blurred

Lily Tomlin guest stars as Penelope Langston, McGee's grandmother. Pictured left to right: Lily Tomlin, Sean Murray and Mark Harmon

The line between McGee's personal and professional life is blurred when NCIS uncovers a connection between his grandmother and the murder of a Navy lieutenant, on NCIS. Lily Tomlin (pictured) guest stars as Penelope Langston, McGee's grandmother.

The line between McGee's personal and professional life is blurred when NCIS uncovers a connection between his grandmother and the murder of a Navy lieutenant, on NCIS. Pictured left to right: Sam McMurray and Mark Harmon Photo: Sonja Flemming/CBS