After Dachau

The story is narrated by a young rich man, heir to a huge sum of money. He devotes his life to an organization called "We Live Again" which investigates the reality of reincarnation. People have souls that pass on to other individuals and give them their memories, usually alongside their own, but sometimes in replace of.
The story focuses on Mallory Hastings, a recently reincarnated woman and her fascinating integration into the new world. She recalls and narrates her experiences and memories of Hitler's victory and him extending his desire for an "Aryan" world to fruition. She realizes all that went wrong. The Nazis had won World War II and purged the world of all non-whites, the rewrote history as to make it known that Dachau, a concentration camp, was instead a battle with Adolf Hitler as its hero.
We find out the human race, now only the Aryan race has taken over the world and killed everyone. Using A.D. to refer to After Dachau, the turning point in their civilization. A.D.-A.D. refers to our A.D. and Mallory was born in this time in 1922.
We find out the Nazi purgings had started to take a cultural effect on America, and very soon Jews were being executed. Blacks were being "repatriated" but as it turns out, just put in concentration camps. Mallory, an Afro-American girl, hid out with her lover beneath the N.Y. underground and made a life until she was caught by the police and executed.
The narrator, in an attempt to bring light to this, contacts a newspaper and other communications to prove this to the world and explain to the Aryans the atrocities they had committed upon the world. As a result, his investigation gets him sequestrated in an unknown location for a short time until he could write three words upon a chalkboard. The words turn out to be "No One Cares" as it turns out, no one does.
The narrator explains that he cares, and he doesn't care if others don't care, he is still going to pursue this for his own personal interest. As he does, he opens an exhibit outlining all the relics from the old world, including works by Jewish authors such as Albert Einstein and Sigmund Freud. The story ends with him receiving a gift from his "uncle" (the man who imprisoned him), which he decides he will probably get published and him opening a shop where he displays pictures of Africans that had been saved in Mallory's hideout. Then one night, someone throws a brick through the gallery's windows, prompting the narrator to conclude that somebody "does care". The last line reveals that the gift is the diary of a young girl written during WWII, the Diary of Anne Frank.