The fifth and final season chronicles the aftermath of last season’s horrific events and finds the characters coming to terms with the consequences of their choices – as they make the realization that if they really want to change their futures, they must first face the past. Helen begins the season involved in an intoxicating new affair. Noah meanwhile has to swallow his pride and his jealousy and step in to take care of his family in her absence. But just when things seem to have stabilized, a chance encounter with someone from the distant past sets in a motion a sequence of events that brings them both to their knees.
Noah embarks on his journey with the Descent movie by getting acquainted with his star, Sasha Mann. Helen mourns a tragic event. Sierra welcomes a new arrival. Joanie struggles with an upcoming birthday.
Janelle struggles with her relationship and work, so turns to Carl for support. Production for Descent commences, and Sasha takes an interest in Helen. Helen takes her first steps towards acceptance.
Sasha proposes adjustments to Noah’s script. Sasha’s relationship with Helen blossoms, and Noah takes notice. Bruce’s condition worsens. Joanie’s business trip leads to violent encounters.
Noah, Margaret and Stacey bond over their mutual distaste for Sasha. Noah attempts to sabotage Helen and Sasha’s relationship. Whitney and Colin face the hardships of their relationship. Joanie visits the graveyard.
Sierra struggles to balance motherhood with her burgeoning acting career. Sierra’s mother visits uninvited. Helen works her first design gig and begins to focus on herself.
In Montauk for work, Joanie becomes acquainted with EJ. Together, they explore Joanie’s family history, leading her to question the cause of her mother's death. Rattled, she starts to make some self-destructive decisions.
Noah and Whitney travel to Montauk to begin planning the wedding. Noah gets a concerning call. Armed with new information about her mother's death, Joanie confronts a stranger.
Allegations against Noah surface and he seeks guidance on how to handle the situation. Helen celebrates a birthday and protects Sierra during an extremely trying time.
As controversy swirls around Noah, Helen and Whitney must decide where their allegiances lie.
As wildfires threaten Los Angeles, Helen and Noah are forced to run for their lives and confront old wounds along the way.