Marianne, studying abroad, pursues an unhealthy relationship.

In a school in small-town west of Ireland, Connell is a well-liked, good looking and athletic student. Marianne is a proud, intimidating and unpopular loner who actively avoids her classmates and questions her teachers’ authority.

Months later, school has finished and Connell arrives at Trinity College, Dublin. He has found a room in a house-share and meets his new housemate Niall. Despite his efforts, he feels out of place and struggles to articulate himself when surrounded by his eloquent and wealthy peers.

Connell and Marianne are back together. Connell has gained confidence in college; giving presentations in class and getting good grades but is reluctant to show Marianne affection in front of her friends. Will the two be able to admit that they are together?

Marianne and Connell are seeing other people and realise (too late) that their break-up was due to a misunderstanding.

Connell and Marianne’s relationship continues in secret and they sleep together for the first time. At school, Connell makes excuses for why he didn’t see his friends at the weekend and evades questions on his mother’s job at Marianne’s house. A girl in his friendship group, Rachel, gets impatient with Connell’s lack of interest and tensions build for Connell.

The night of the Debs is approaching and the girls at school have organised a fundraising event. Marianne has been asked to help and is out of her comfort zone. At the club, one of Connell’s friends Karen does her best to show Marianne some kindness but Rachel behaves coldly towards her.

Connell joins Marianne's social circle but doesn't fit in. He apologises for how he treated her; she reconsiders her relationship with her new boyfriend, Gareth.

Connell visits Marianne at her family's summer home in Italy, where tensions between her and Jamie are at an all-time high.

Marianne has returned to Carricklea for the summer. She and Connell spend their weekends together, even though he is still living in Dublin. After a night out together, they start to discuss their friendship and inevitably their attraction.

After a tragic event, Connell struggles with severe depression. Marianne remains a lifeline for him from abroad.

Marianne and Connell are back in Dublin and together as a couple. Life is calm and they are at ease with each other. Then Connell receives news that he has been offered a place to study in New York. Neither of them know how to process the news and so they decide to let it sit.