A lonely twentysomething, Becky Green, becomes obsessed with the suicide of her estranged childhood friend Chloe and assumes a new identity as Sasha to engineer a "chance" meeting with Chloe's best friend, Livia, at an art event, followed by another run-in at a yoga class.

Sasha then infiltrates Chloe's group of close-knit friends. She also gains a job outside her genuine work experience through Livia's contacts as she attempts to discover why Chloe died. Through her new alter-ego, she leads a life that is far more exciting than her life as Becky.

A series of flashbacks reveals that Becky had two missed calls from Chloe minutes before her death. As Sasha, Becky eventually uncovers the truth of Chloe’s clandestine activities she has hidden from her husband and friends.

Becky starts an affair with Chloe's widowed husband, Elliot; whereas the rest of the group including Elliot's mother disapproves of their relationship. Elliot decides to run for election, Becky and Livia run his campaign along with Elliot's friend Nish.
Who is Sasha? How does her life compare to Becky?
Sasha is a new identity assumed by Becky in order to engineer a "chance" meeting with Chloe's best friend, Livia, at an art event, followed by another run-in at a yoga class. Becky continues to live life as both Becky and Sasha. Sasha infiltrates Chloe's group of close-knit friends and ends up gaining a job outside her genuine work experience. Sasha leads a life that is far more exciting than her life as Becky.