When Donny the Unicorn is hunted by a seemingly unstoppable foe, the Powerpuff Girls have to find a way to save him before it's too late.

At a retirement home, Buttercup meets an old woman claiming to be Green Wing, a former superhero. When her former nemesis reemerges, Buttercup teams-up with Green Wing.

Princess Morbucks throws her 6th birthday party and being the only one not invited, Blossom tries to keep Buttercup, Bubbles and the Professor at home so they won't go.

Blossom thinks she's a shoo-in for the lead role in a school play. When the list comes out, it's Bubbles who wins the lead role. Blossom, resigned to playing a rock (with no dialogue at that), Blossom tries to sabotage Bubbles' appearance until a Viking queen shows up after being summoned from a book (from which the play's script comes) and takes the male lead, Jared Shapiro, to get him to marry her.

Getting ready for the new Space Tow Truck movie, Bubbles keeps explaining to Blossom and Buttercup that Bliss exists, the two don’t seem to believe her though. At the theaters, an old-timey character breaks through the screen and the Girls prepare to fight him. Eventually after calling her multiple times, Bliss finally appears and defeats the villain, but the Professor, deeming her too dangerous, stuns her and knocks her out.

Bliss' backstory is revealed, by the Professor, Bliss herself and even Mojo Jojo.

When Bliss can't control her powers, the Girls must help her, whilst dealing with repeated attacks from the Gnat.

When the Professor thinks Bliss is not ready to fight crime, she must prove it by doing with the Girls; they are unaware that Mee (Bliss' pet elephant) is actually Him in disguise, wanting something bad to happen so that he can merge with Bliss and use her powers for his own ends.

With Bliss possessed by Him, the Girls must save Bliss and stop Him once and for all before he splits Townsville and the Earth in two.