Iris Boelens (Angela Schrijf) is a lawyer whose son Aron (Daniel Verbaan) is having increasing difficulties in school, leading his teachers to think he may be autistic. While Iris and Aron are staying at the home of Iris's mother Ageeth (Monique van de Ven) Iris learns that she has an autistic half-brother she never knew about named Ray (Fedja van Huêt), who has been locked in an institution since 1982 for the murder of prostitute Rosita de Waal (Maartje van de Wetering) and her infant daughter Anna. Iris becomes convinced that Ray is innocent, and takes on his case so she can prove it.
Daylight contains examples of:
- Big "NO!": Ray repeatedly screams "NOOOOOOOO!" whenever he has a meltdown.
- Disappeared Dad: Ray's dad walked out - as Ageeth puts it, "He came, he saw, he left." He later remarried, and although he carries on an affair with Ageeth for two weeks per year, he hasn't had any contact with Ray for decades. His last interaction with Ray involved framing him for murder to protect Ageeth. Iris doesn't even know who her father is, and Aron's father is never mentioned. Ageeth tells Iris, "We're not good at holding onto men."
- Family Relationship Switcheroo: Iris learns that she was born Anna, the daughter of Ray and Rosita, making Ageeth not her mother but her grandmother.
- Flashback: Ray has many flashbacks to his relationship with Rosita.
- Hooker with a Heart of Gold: Rosita was always kind to Ray, and he has nothing but fond memories of her.
- Impairment Shot: A flickering image and static noises are used to represent Ray's feelings of overwhelm.
- Luke, You Are My Father: At the end of the movie, Iris tells Ray, "Baby Anna's not a baby anymore. You are my father. You are my father." Ray embraces her, and they walk out of the institution together.
- Never Found the Body: Anna's body was never found. This is part of the reason Iris thinks Ray is innocent - she doesn't think he would have been clear-headed enough to hide the body. Sure enough, it turns out that Ageeth adopted Anna and changed her name to Iris.
- Scars Are Forever: Iris has scar tissue covering much of her upper back. Dina de Waal drunkenly spilled boiling water on her when she was a baby.
- Struggling Single Mother: Iris struggles to raise Aron by herself, especially since most babysitters won't take him anymore. When he gets suspended for a week, she takes him with her while she investigates.
- Their First Time: In a flashback, Rosita offers to have sex with Ray, and he accepts. The two start a relationship, leading to the conception of Anna/Iris.
- Your Makeup Is Running: In a flashback, streaks of makeup run down Rosita's face as she begs Ageeth not to take baby Anna away.
