Recent advances in scene-based video generation enable coherent visual narratives from structured prompts, yet a key aspect of storytelling -- character-driven dialogue and speech -- remains underexplored. We present a modular pipeline that transforms action-level prompts into visually and auditorily grounded dialogue, enriching scene-based storytelling with natural voice and character expression. Our method takes a pair of prompts per scene, defining the setting and character behavior. While a story generation model such as Text2Story produces the visual scene, we focus on generating expressive, character-consistent utterances grounded in both the prompts and a representative scene image. A pretrained vision-language encoder extracts high-level visual semantics, which are combined with structured prompts to guide a large language model for dialogue synthesis. To maintain contextual and emotional consistency across scenes, we introduce a Recursive Narrative Bank, a speaker-aware, temporally structured memory that accumulates each character's dialogue history. Inspired by Script Theory, this design enables dialogue that reflects evolving goals, social context, and narrative roles. Finally, we render each utterance as expressive, character-conditioned speech, producing fully voiced, multimodal video narratives. Our training-free framework generalizes across diverse story settings, providing a scalable solution for coherent, character-grounded audiovisual storytelling.