Ooh I actually have a story like that tucked away in my drafts somewhere. Forgot about it until now. :-D
That's an interesting premise for a story.
Because I am a technologically challenged klutz I suspect I would go through that portal and inadvertently kill both my grandparents...
Chortling and rubbing my hands together... Monsanto? Dead in the water!
I'd step on a bug and cause the whole planet to explode
Ahem! Did you peek inside my C Drive?
As I learned from "The Butterfly Effect," if you go back and change something in your past, chances are you'll come back and find that it messed up something that's great about your life now!
This is stirring the juices.. great prompt!