Several people have now approached me asking for permission to create some kind of adaptation of my short story The Difference - usually a short film. I've said no each time, for the same reason each time.
The Difference must be presented in the form of a text transcript. It has to be kept in this medium because the whole point of the story is to leave as much uncertainty as possible as to whether the character Z is a human being or not. It is critically important that the final conversation between Z and I causes the reader to re-examine the evidence and realise that there is actually no evidence to support that Z is real/human. This twist is where the story gets all of its power from.
Adapting the story to any kind of visual medium would almost certainly involve granting Z a human face (or a chatterbot's face) and a human voice (or a simulated electronic voice), which heavily weights the possibilities in one direction or another, in a way which doesn't happen in plain text. Even changing the format of the text from a chat log to a conventional narrative with dialogue sacrifices some of the ambiguity.
In fact, what is true of Z is also true of all of the other characters in the story. Each of the characters A, B, C, D, E, F, G and H (and the others who are implied to have made contact too) could be an artificial person sent by I to test Z - or could be I under different names. It seems like a no-brainer that I is real, but even that is uncertain. In the end it's just a chat log. All the evidence is textual, none of it is "physical". This is one hundred percent deliberate and one hundred percent critical to the story.
You could retain the chat log format and film the messages as they come up on a computer screen, but what would be the point?
That, at least, is what I've said each time. If you have thoughts, leave them in comments below.