Three or four nights ago I had an interesting dream. I had a time travel dream. I was from the future and was sent back to Nazi Germany to assassinate Adolf Hitler. Time travel was not a physical event but a psychic one. The mind of an individual was not sent back physically but mentally. The mind of the time traveler was sent back to occupy a chosen person who was considered to be weak minded enough to be overshadowed by a projected stronger mind. The stronger mind would take over the weaker mind who would simply be unaware or asleep to the stronger dominant mind. The stronger mind would control subconsciously while the host mind would go on thinking it was in control. Compatibility of the minds was established by genetics in that they had to be relatives. Their genes connected their two minds.
The guy I was sent to occupy, was a distant German ancestor I never knew I had. (I had no idea of when in the future I was from, or what race or ethnicity I was.) Once a traveler was established in a host, the host never knew that their actions were really not their own. Subconsciously the “guest” controlled all that the host did.
When the mission was complete, the time traveler would slingshot back to their own time after the death of the host. This could happen anytime after the specific event that the time traveler was sent back to correct or fix. In my case this event was the assassination attempt on Hitler that was known as operation Valkyrie. This is when some of Hitler's generals tried to kill him with a bomb planted at a meeting place known as the Wolf's Lair. Of course as history tells us Hitler was saved by a heavy oak table that protected him from the explosion. When the bomb was planted, the assassin put it under the table so that it would not be noticed. Which it wasn't but the table protected Hitler and the plot failed. Hitler's revenge took the lives of over two hundred men.
Now, the problem with time travel, is that if you go into the past and change an event, especially an important historical event, you could change all of history. You could change it so much that you could prevent your own birth and that of your parents, or grandparents. You could create disasters that had been avoided by certain people who no longer exist or who were not where they were supposed to be at the right time. This would be caused by of the tampering of time. So to avoid these problems the traveler could only be allowed to effect an event that was going to happen which the changed effect would be minimal in the overall impact in world events. The first safety rule: No physical time travel. Time travel would have minimal effect if the agent was a person born and living in the era he wished to penetrate. Then the agent would find a crossroads event where he could affect a change in a small event which would have a very small ripple if the opposite of what originally happened, happens.