In the 64th century, Abra Kadabra began having dreams of his Pre-Crisis life. He ran all the tests he could on himself which led him to the conclusion that he was suffering from neuro-temporal displacement caused by The Flash changing the timeline. He went to the Flash Museum to investigate further where he found a broken Martian Memory Restorer which he fixed and used on himself.
He then travelled back to the past to erase Central City with an antimatter bomb as revenge for this and used the restorer to display an image of his family to The Flash, only to discover that his life was changed by the Crisis and not only by a timeline change.
Martian Memory Restorer