https://ifdb.org/viewgame?id=hqjjswyesj1gjm7v

They all stare at you expectantly, like children waiting to be told a bedtime story. Who can blame them? You are, after all, Antoine Saint Germain, the great French detective. No criminal has ever been a match for you, and everybody is looking forward to a description of your brilliant deductions.

There is just one small problem. One tiny detail that makes it different this time. A mere trifle, really. This time you have no idea who did it.

Step into the shoes of we-have-Hercule-Poirot-at-home and face the greatest challenge of your career. All of the suspects have been gathered for the dramatic pronouncement of the guilty party and the revelation of each of their individual secrets and peccadilloes. Unfortunately you have nothing to reveal; you've drawn a complete blank. Now what ... ?

Figure out the puzzle through a conversation system, where you type in the topic you wish to discuss and Saint Germain translates it into dialogue. By choosing the right topics and sifting through the information you find, you can bluff the suspects, draw them out on each topic, and eventually come up with the perfect accusation.

(I am linking the IFDB page because the itch.io page has remarkably little info. Still, you will probably want to pick up the itch.io version, as it contains the .gblorb file. .gblorb files will work with any Glulxe interpreter, and are thus OS-independent.)

Multiple versions available.