As part of Infinite Journeys Challenge
"The First Ancestor"
It is a story about the Robot who was tasked to save the first Ancestor of his Creator's family. His Creator was blamed for the crime that he never committed. The penalty is to extinguish all of his Creator family heritage from existing in the timeline history. Their first Ancestor or their last survivor still is a young Ape from 300k BC. The Robot and Young Ape have to escape thru the "Time express" that travels across the branch Timeline.