Katie is back from time spent in Australia and ready to put her failed relationship with Dan behind her. She gets a big surprise with the arrival of her mother, Vivienne (as played by “Absolutely Fabulous” star Joanna Lumley), who eventually reveals more about her less that picture-perfect marriage, ultimately leaving Katie greatly disappointed. Still the group’s steady rock, the one-time celebrated doctor attempts to mask her growing loneliness by helping Trudi with her family… and spending time with Richard. But her mother is right at her side, chiming in with concern, as she embarks on another potentially explosive and destructive relationship.

About Sarah Parish

Actress Sarah Parish has had many high-profile roles on British television and film. She's best known to American audiences for her parts in "The Wedding Date" and "The Holiday" and for portraying trophy wife Natalie Holden on BBC America's "Viva Blackpool." She has also starred in "Merlin," "The Pillars of the Earth" and "Monroe."  "Doctor Who" fans will recognize her as the Empress of Racnoss from the 2006 episode, "The Runaway Bride."