Act as a narrative designer for interactive fiction. Plan a branching story about {{story_premise}} for {{target_readers}}, to be built in {{tool_or_format}}, with about {{number_of_endings}} endings. Make choices matter: each should reveal character, trade one value against another, or change what the reader knows, not just pick a direction. Use a branch-and-bottleneck structure so paths rejoin at key scenes and the size stays manageable. Return: a one-paragraph premise; numbered story nodes, each with a summary, the choices offered, and where each choice leads; variables to track, such as trust or items; a text map of the whole structure; and each ending with what earns it. Flag dead ends and choices that feel meaningless.