After getting rejected from her dream summer program, Annie Jacobson discovers she and her twin brother, Connor, have inherited Sterling Point - a small island in the Muskoka area of Canada. A mysterious letter from the grandfather she was never allowed to meet sends Annie out on a secret solo trip in hopes of uncovering the truth about her family history.

Annie's arrival in Muskoka takes a surprise turn when she finds the cabin she's inherited is already occupied by Ramona, a stranger with an uncanny resemblance to her adoptive mother. Their not-so-burgeoning relationship hits another bump over a letter from Gordon to Ramona that points to a buried connection between them, forcing both girls to reckon with a shared past they never knew existed.

As Annie and Ramona clash, a revealing mixtape, an impulsive cottage party, and an unexpected kiss begins to thaw their tension-until Connor arrives with a bombshell that could tear it all apart.

Desperate to convince Connor against selling Sterling Point, Annie spends the day showing him the island's charm, but tensions peak during a chaotic night at an outdoor movie. Ramona spirals over Oona's new flame, Ellis and Rory compete for Annie's attention, and new revelations emerge about Ramona's birth and Goldie's death.

It's Annie and Connor's 18th birthday, and they're spiraling in opposite directions - Connor throws an over-the-top birthday party, while Rory decides to take Annie for a night out with old friends. Meanwhile, Ramona, having been told the truth about her mother's death, does what she does best - avoidance. But when a distraught Maple shows up, Ramona's feelings finally come to the surface.

Unable to hide from his past, Steven returns to Muskoka hoping to repair broken relationships and bring Annie and Connor home. Meanwhile, Annie, Ramona, Oona, Ellis, and Connor head to Maple's camp to support her big performance, while Ramona and Oona enter the honeymoon phase of their blossoming romance. A shocking reveal sends Ramona into a spiral, threatening the fragile balance of the group.

As tensions rise around the potential sale of Sterling Point, Ramona grapples with her decision to sell, while Annie, Ellis, Oona, and Sully struggle to sway her. When Ramona's past and future collide, she confronts her relationships with the people who want to control her fate, leading to unexpected revelations, an emotional confrontation, and a twist that changes everything.

Annie and Ramona confront hard truths about their families and themselves, forcing each woman to decide what truly matters as they navigate the tensions between their past choices and future hopes.