Most of the work was not the code. It was getting one scene to come out the same way every time from two random photos. A few things I changed along the way:

1. Say who is who in plain words. The first photo is the one who turns, the second is the one holding the gun. When the prompt left this vague, the model sometimes swapped them.

2. Name what you don't want. My first test render gave the zombie bloody tears. Adding "no bloody tears" to the prompt fixed it on the next run.

3. Write the beats in order. Raise the gun, hesitate, lower it, step in, hug. Ten seconds is short, so each beat gets roughly two seconds and nothing else.

4. Expect long renders. With Seedance 2.0 my test renders took 274 and 388 seconds, so the page lets people leave and come back instead of staring at a spinner.

The prompts behind the sample clips are on a free page if you want to try them in your own tool: zombie couple video prompts. The tool itself is at zombie-couple.com.