SPOILER ALERT & CONTENT WARNING: SEXUAL VIOLENCE / SUICIDE.
Let’s look at the structure of Episode 1 and see how writer Sally Wainwright weaves the 4 story threads together:
NB: The A story (trilogy) refers to the story overarching the entire 3 seasons. A story (season) means the story which expands throughout Season 1.
I have broken the episode into 5 acts:
Episode 1 opens with Catherine’s day to day – police procedure – not related to either A story (season) or A story (trilogy).
The following scene after the opening credits starts off the A story (season).
Scenes 4/5/6 refer to the A story (trilogy).
Midway through Act 1 Catherine kisses her ex-husband – already with someone new – referring to her personal life. She still has a thing for her ex-husband.
Then, we’re back into the Season story.
Next, trilogy story.
Then 2 scenes which set up the season story (the inciting incident)
The final scene of Act 1 cleverly weaves together both A story (season) and A story (trilogy) around antagonist Tommy Lee Royce.
Act 2 opens with conflict between Ryan and Catherine – A story trilogy.
Next 2 scenes A story season.
Then 2 scenes C story.
Finally, A story season.
Act 3, the central act of the episode, begins with A story trilogy telling us the reason for this Protagonist / Antagonist battle – an immensely powerful scene where Catherine tells Ryan’s teacher the entire backstory of her daughter Becky, Lee Royce’s violent sexual assault and Becky’s consequent suicide.
We might call this the midpoint.
The following scene takes us to Catherine arranging to meet ex-husband Richard. I have included this as A story trilogy, as opposed to B story (family) because it leads up to Catherine’s expression to Richard of her absolute hatred of Tommy Lee Royce.
The next 3 scenes are dedicated to A story season.
Act 4 is completely dedicated to A story season.
Scenes 38/39/40 focus on A story season.
Scene 41 refers to police protocol as Catherine tells an amusing story to Kirsty about drugs.
Then, she spots Tommy Lee Royce, midway through the final act.
The final 4 scenes of act 5 all represent the season A story.