The island had had enough of the rain, and the portents, and the rising levels of the water. Perhaps this was going to be the flood that drowned Atlantis, or perhaps it wasn't, but she wasn't planning to stick around to find out. And so, somewhere in the dark of the night, she pulsed briefly with light and then vanished.
Only to pop up again in the middle of a river, a few miles away from the center of a large - for its time - city. The island pulsed with light one more time, then laid still. The water crashed against her shores with violent confusion, but the land mass didn't budge.
When the sun came up, so would the people of Regency London, the rich putting on their
pretty frocks and striding from beautiful landmark to beautiful landmark. The poor, on the other hand, would go on drinking, working, and passing around books of a dubious but highly entertaining nature, among other things.
Neither would as much as cross the other's reality.
It was a crisp 65F in London today. The sun was shining behind the clouds, and not a drop of rain would fall today.