After the disappearance of Negaduck by reuniting him with Darkwing Duck, it was strange to see another duck with the same outfit as DW running around the streets of St. Canard. Seeing that DW did not get shot with gamma rays to separate the negative charges from the positive charges, we start to believe that this criminal is a real live being who doesn't have anything to do with Darkwing Duck.
Or so we believe.
Following Negaduck after a brilliant heist from the Fearsome Five, they discover that his secret lair is actually inside a large birthday cake that leads to an alternate dimension.
Now, we know that Negaduck comes from a parallel universe from Darkwing's where complete opposites are the dominant trait of the parallel St. Canard.
The only thing that bothers me about how the writers set the plot up was that Gozalyn is a really sweet duck. If the laws of opposites are to be corrected, she should have been an evil duck because in the good alternate universe, she's mostly a do-gooder that also loves to fight crime.
Well, I suppose that if she wasn't good, then we wouldn't see a touching moment where DW's parental instincts come into play in promising to also protect this Gozalyn from the evil menace Negaduck.
Good storyline, 10/10. :)