Eh, it isn't rally an "idea" but more of a start of brainstorming.
I freely admit to being more suited to world building than story writing, but I do believe a sufficiently developed world is a story on its own, with a slow reveal of everything with in.
Some may disagree... more power to them.
The fact remains that it is possible to build a great story working backwards from a built world...
For now here is some more brainstorm: A really bad one that has no real use, but one none the less.
Technology:
Nanites: Mini-Robots who can harness either "zero point" energy or "Higgs field" energy.
Using the Nanites and networked together results in augmenting the human body to be able to use Magic.
History:
A hundred thousand years ago Humans evolved enough to develop these nanites, and they multiplied and ran rampant through the human population. Politics led to some control programs being built in to prevent insubordination, and over all the greatest break through of all time led to the enslavement of the entire human race to a few people
During this time the human race colonized mars possibly if it is important to the story. Otherwise not.
Also Animals that were experimented on resulted in the evolution of all of the magical animals, genetics augmented with nano robots.
Human experimentation lead to the non-human but human-like races. IE Races that speak the human language.
Centaurs, Merman, Veela, Goblins, Fairies, Yatta Yatta.
Nano-robotics also created two primary diseases: Vampires and Werewolves.
The Nanites of the infected either:
A) Call for nanite rich blood to replace their own failing nanites
B) Mutate the nanites of the person bitten.
Also Three Critical Directives were instilled into the robots. Control, Punishment, and death.
Over two thousand years later the controller of the human race realized everything was all fucked up. He decided it was bull shit and wanted to free everyone.
So he did.
Before doing so he used them to remove all race that their civilization existed. All of the technology was destroyed.
Before he freed the people he used the nano-robots to destroy the memories of the human-slave-robots.
The final command was for them to become undetectable before they deactivate their ability to harness energy, to remove the ability from all of them to manipulate the zero-point/Higgs Field energy.
So people come out of their "coma" and thousands of years latter people speak of the fallen civilization of Atlantis and the great Wizard Merlin who did... something right?
So at times random nanites who are recreated when people are conceived, come on-line instead of being inactive. Also people who had their nanites reactivated are more likely than not to have their off springs nanites reactivated.
Now when Merlin died he locked absolute control of the "Human Emperor's" seat away in three objects scattered across the land.
The first was a clock marked by the Nanites to be unseable. Anyone who has nanites, active or not, will be tricked into thinking nothing is there. The little clever robots will recreate in astoundingly correct detail what should be seen.
The second was the original control rod encased in wood, with the most unlimited access to all of the nanites abilities.
The third was a stone that gave access to the database of former nanite users. When a user of nanites dies, their nanites memory is returned to this database. Sometimes a few of the nanites go into paintings if they were bound their instead. Other times large percentage of the nanites are put into objects which could eventually be used to create a facsimile of the original, similar to the stone but more accurate.
At random times the holder of the nanites may order their nanites not to return to this database. when this happens they create ghosts.
Other times nanites of the dead can congregate in great numbers on their way to the database. If this happens Peeves is created.
If the three control items are reunited, the holder becomes the new Merlin, and if they know about can re-enslave the human race.