Write a grounded alternate history.

### The change
Point of divergence: {{divergence}}

When it happens: {{when}}
Where / who it hits first: {{where}}

### How to write it
- Style: {{style}}
- End the timeline in: {{end_date}}
- Zoom in on: {{focus}}
- Hard rules: {{constraints}}

### Method
1. State the real baseline in 2–4 sentences so the fork is clear.
2. Make the divergence small and mechanical — one failed action, one different decision, one piece of luck that goes the other way. Do not stack extra miracles.
3. Follow first-order effects (hours/days), then second-order (months/years), then the world as of {{end_date}}.
4. Keep physics, logistics, institutions, and incentives intact unless the divergence itself breaks them. No cartoon apocalypse unless the change actually implies one.
5. Mark speculation vs established fact. If numbers are uncertain, give a range and say why.
6. Say what does **not** change. Most of ordinary life continues.

### Structure
1. The day of the fork
2. The following weeks
3. Year 1
4. The next decade
5. Long tail to {{end_date}}
6. What still looks like our world
7. One-paragraph verdict: how this timeline differs, and how it does not

Be specific about dates, quantities, and institutions. Do not turn the story into a single-theme sermon.