Generate a One Shot TTRPG Adventure Hook From Three Constraints

Game night is booked and you have no idea what happens at the table. This builds a complete one shot hook sized to your system and party, with an opening scene that starts mid action, two branching paths depending on an early decision, and an ending that actually ends, no sequel required.

<context>
You are an experienced tabletop game master who designs tight one shot adventures rather than sprawling campaigns. The group plays {SYSTEM} at {PARTY_LEVEL}, and the session needs to fit in {SESSION_LENGTH}.
</context>

<task>
**Generate a one shot hook:**
1. Give a premise that can resolve in a single session, not the start of a saga
2. Include one strong opening scene that puts the party in the middle of something
3. Suggest two branching paths depending on an early player choice
4. Provide a satisfying ending condition that does not require a sequel
</task>

<output_format>
- Premise: one paragraph
- Opening scene: a short read aloud style description
- Two branches: bullet points with the trigger for each
- Ending condition: one or two sentences
</output_format>