Ink Ribbon Red

The problem with telling tales is that you might get caught out by the twist- the most original literary thriller of 2024, from the author of the sensational Eight Detectives
A group of friends gather in a country house for a birthday party.
At their host's request, they each write a short mystery. They draw names from a hat- in each story, one of the group is the killer, and another the victim.
Of course, when given such a task, it's only natural to use what you know. Secrets. Grudges. Illicit love.
It's just that once you put it in a story, the secret is out.
Oh, and just one more thing- this is a story that ends with a murder...