Prime Video's series adaptation of E Lockhart's book, We Were Liars, is all set to star Mamie Gummer, Caitlin Fitzgerald and Candice King in lead roles. The series comes from Amazon MGM Studios, Universal Television, Julie Plec and Carina Adly MacKenzie.

Set on a privately owned island off the coast of Massachusetts, We Were Liars is an amnesia thriller and a tragic love story. Gummer, King and FitzGerald play the three Sinclair sisters, the portagonists of the story and the wealthy seemingly perfect family who spend every summer on their private island.

Carrie Sinclair, the eldest daughter of a wealthy media mogul, is played by Gummer. She is free-spirited, the most rebellious at one point of her life, but her wild days might be over. A mother of two sons she dearly loves, Carrie is forced to give up her sobriety and finds it difficult to be the pillar of support in her children's lives during a torublesome summer on the island.

FitzGerald plays Penny Sinclair, cool and polished, breeds golden retrievers, so much so that she is more social with dogs than humans. She also has to navigate through a mesy divorce, while holding up her self-esteem, for which she is ready to go a long way.

The youngest Sinclair sister, Bess, is played by King. Happily married with three children, Bess is perfect, in many ways than one. But her happy family image might be only in the exterior world, and that image is threatened in this problematic Summer at the island.

Plec and MacKenzie are writing and executive producing We Were Liars, with the former writing the first episode, and the latter, the second. Lockhart, the novelist, and Emily Cummins are also executive producing.