Curate, connect, and discover
Due to issues with Jack’s fertility, the Fenton kids were both conceived using donor sperm. The donor they ended up receiving wasn’t anyone special; just a random chemical engineer from Gotham City by the name of Jack Napier
And perhaps things could have ended there. Perhaps in another reality, they did, and Danny never had to pay more than a passing thought to his genetic father.
But in this world, Jack Napier faced one extraordinarily bad day, and it broke him. All he could do in response was laugh at the utter meaningless of it all. And by the time his cackles subsided, the man he had once been was dead. In his place, only the Joker remained.
Yet despite how suddenly everything changed, neither of them knew the truth of things right away. The Joker had never even known he had a son, since the service didn’t inform people if their donations were used. And though Danny had known Napier’s name, he had no reason to pay enough attention to the man to notice his disappearance.
That ignorance couldn’t last forever, though.
All it took was a few medical tests from Danny before the automated database systems made the connection.
And that certainly didn’t go unnoticed by those in Gotham.
It looks like it’s time for Uncle J to pay his kid a surprise visit! Ooh, maybe he could break out the ol’ electroshock kit and bring back Joker Jr too, make it a proper family reunion!