When Em a famous Hollywood actress' best friend Doll breaks up with her partner back home in London, she invites her to LA to work for her as her assistant.

At a party, Doll babysits for Susan Sarandon however when her child doesn't like the game they play he throws a temper tantrum causing tension between all of the guests and Doll & Em. Later the organiser of the party, Buddy asks the girls to stay to join him in his jacuzzi.

Doll gets to be an extra in a scene Em is finding it difficult to show emotion in. The tension between the pair mounts as Em feels more and more pushed out by Doll. Later when she Em sends her to get the pair a coffee, Doll fakes a disability in order to remain in a parking space and ends up fracturing her ankle.

Doll's ex, Tom, is trying to get back together with Doll and get her to come back home. Doll is still recovering from her accident but when Em tells her she's going to set without her, she decides it's also time to return to work. The flurry of support gets puts Em off the big scene she has to film for the day as she feels more and more pushed out by her best friend.

Doll receives a casting call back to London for the part that she and Em went up for. But has yet to tell her, as Em is panicking that she doesn't have another movie to work on once this one has wrapped. Aware that Dolly is going home, Em tries to get her to stay by getting Andy Garcia to come to the set and tell her about the vacant assistant position he has. Dolly admits the truth to Andy as production on the film wraps. As the friends pack up the house, Dolly receives a call saying that the moving company will be a day late. Em can't understand why she won't just reschedule her flight and Doll finally tells her about the callback. The girls have a huge argument as Em's family come to pick her up and Buddy drives Doll to the airport.

Back in London Doll didn't get the part and has ended up back at the restaurant she worked at before she left for LA. Unaware of this Em is back for Christmas with her family and since both girls Dads used to take them to the same restaurant a awkward encounter between the once best friends occurs. The manager of the restaurant senses the obvious tension and plants a flyer for a show Doll is appearing in, in the bag containing the food Em takes away. Em goes to see Doll's show and at the after party finally has the opportunity to fix her friendship.