2x23 - The Powerpuff Girls

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.