Plot summary
Walter Jameson, a professor of history at an unnamed college, is engaged to one of his doctoral students, Susanna Kittridge. Susanna's father Sam, another professor at the college, becomes suspicious of Walter, who does not appear to have aged in the twelve years they have known each other and seems to have unrealistically detailed knowledge of some pieces of history that do not appear in texts. Walter at one point reads from an original Civil War diary in his possession. Later, Sam spots the diary's author, Major Hugh Skelton, in a Mathew Brady Civil War photograph and finds that Walter looks exactly like Skelton.
After Sam presents the evidence, Walter admits that he is indeed Skelton, but is far older, and implies he knew Plato personally. Fearing death as a young man, he offered himself to an alchemist seeking to devise a means of immortality. Walter woke up to find the alchemist missing and at first believed that the experiments failed but then had to watch as his family and friends grew old and died while he remained young. Having become cynical and embittered after centuries of wandering the Earth and changing identities, Walter purchased a revolver some time ago to commit suicide, but has lost his nerve and now hides it in a desk drawer.
When questioned, Walter admits that he loves Susanna, but that he has also loved many women before her, and that he will have to eventually leave her. Horrified, Sam refuses to consent to the wedding. An unmoved Walter then tells Susanna that they will elope and get married that evening. He dismisses her father by telling him that he has no actual proof of his immortality and people would think him insane if he persists.
Stopping to collect some things from his office, Walter is confronted by Laurette Bowen, a widow who identifies him as her "late" husband Tom. Having found the gun on his desk, she shoots Jameson in the chest and leaves. Sam finds him and watches as Walter, now at peace, rapidly ages and collapses on the floor. Susanna arrives and Sam tries to stop her, but by the time she forces her way past him, all that is left of Walter is his clothes and shoes covered with dust. When Susanna asks what is on the floor, the professor replies, "Dust, only dust."
Credits
Adapted from Wikipedia contributors, Long Live Walter Jameson. Paragraphs and formatting adjusted; illustrations, reference markers, block quotations and non-story material omitted.