AU where in 2030 England gets sent back to the 1920s by accident after America and Russia shows him their newly invented time machine. He ends up meeting himself, but he looks a bit weird compared to what he remembers.
It’s now up to the two Englands to help him get back to his own time again. :UU
Imagine Person B finds out that Person A is possessed by some kind of demon that attempts to take over their soul. B now does everything to prevent this from happening. How they try to accomplish it and whether it works is up to you.