Book scenario
Nearly everyone could remember the moment the holographic spot appeared on their hand. It would be almost impossible to miss the thin black 25 mm ring with a white centre. But it only happened to humans over the age of seven years old because this was the age that the Sheen considered the people who inhabited earth should arrive at a time in their lives when they became aware of the difference between right and wrong.
And the spot ….. well it was put there for a very specific reason.