I have been unable to find the name of a story I read in high school more than two decades ago. I believe it was in a collection of sci-fi short stories.
The short story begins with the protagonist (a reporter or bodyguard I cant remember) who is following a diplomat at some sort of international conference. The reporter follows the diplomat through a door and ends up in a meeting room with a bunch of other "time travelers" who are from different times in the future. The diplomat is seeking help from the people of the future, either technology or something else.
If I remember correctly, the reporter/bodyguard becomes upset when they refuse to give technology to help the diplomat, and he is immobilized by some special device on one of the people from the future. The meeting ends shortly after one of the "time travelers" from the farthest in the future says something like "No matter what successes or failures happen, no matter what great achievements you make, I will be the end result," as he is the last human alive in the universe.
After the reporter and the diplomat return to the present, the diplomat claims to have no memory of the events that transpired in the story.