B-Story

Structure

Definition: The B-story is the secondary plotline that runs alongside the main story (A-story) in a screenplay. It often involves a relationship, a thematic counterpoint, or a subplot that mirrors or contrasts with the protagonist's central journey. The B-story typically intersects with the A-story at key structural points.

Understanding B-Story

The B-story is not filler — it is the thematic engine of the script. In "Finding Nemo," the A-story is Marlin searching for Nemo. The B-story is Nemo gaining independence in the tank. Together, they explore the same theme: letting go. The best B-stories illuminate the A-story from a different angle. They often carry the love story, the mentor relationship, or the moral argument that the protagonist needs to understand before they can win the climax. In TV, the B-story usually involves supporting characters and intersects with the A-story by the episode's end. In features, the B-story typically launches in Act I, runs through Act II, and resolves just before or during the climax.

Example in a Screenplay

A-STORY: Detective Reyes hunts a serial killer across
the city.

B-STORY: Reyes's daughter is failing out of school.
Reyes keeps missing parent-teacher meetings.

INTERSECTION (Act III): The killer targets the school.
Reyes must choose between the case and being present
for her daughter — resolving both stories at once.

Common Mistakes

Writing a B-story that is completely disconnected from the A-story thematically. Making the B-story so interesting it overshadows the main plot (or so boring the audience skips it mentally). Forgetting to resolve the B-story before the script ends. Starting the B-story too late — it needs enough screen time to feel earned.

Related Terms

Structure

Three-Act Structure

Three-act structure is the foundational narrative framework dividing a screenplay into setup (Act I)...

Structure

Midpoint

The midpoint is a major story event occurring roughly halfway through the screenplay (around page 55...

Character

Protagonist

The protagonist is the central character whose journey drives the screenplay. They are not necessari...

Character

Foil

A foil is a character who contrasts with the protagonist (or another significant character) in ways ...

Character

Supporting Character

A supporting character is any character who serves the story without being the protagonist or primar...

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