The Holiday Special, published about a year and a half after the original Power Pack series ended at issue #62, brought back the original creative team: Louise Simonson and June Brigman. It also essentially undid all of the storylines begun in the last six issues of the regular series, which had been created by a new creative team and intensely disliked by readers.
At the end of the original series, the Power Pack, and their parents, were en route to New Kymellia in their smartship, Friday. Alex had turned into a Kymellian and Margaret Power had lost her mind.
In the Holiday Special, it was revealed that Alex and both of his parents had been replaced by pseduoplasm doubles. The parents had originally been kidnapped by Queen Maraud and a renegade Kymellian Technocrat for James Power's scientific genius and knowledge of matter/anti-matter conversion. Alex had been replaced when he noticed something was amiss with his parents. Alex's double had turned into a Kymellian because it was reverting to its old programming, and Margaret's double had malfunctioned. The real Alex, Margaret and James Power were all in captivity on the Technocrat's ship.
When Julie Power noticed that something was wrong, during the flight to New Kymellia, she was teleported into captivity by the Technocrat, where she was reunited with her brother. Alex and Julie, working together, managed to disrupt the Technocrat's console, which caused the pseudoplasm doubles of Alex, James and Margaret to collapse and melt in front of Katie and Jack. With Friday's help, they jettisoned the pseudoplasm into space so it could not return.
Friday, Jack and Katie reached the Technocrat's ship, where the remaining Power siblings set out in search of Alex, Julie and their parents. All four siblings were reunited, and were then tasked with finding their parents and finding their way out of the ship. Along the way, they were somehow able to switch their powers several times as necessary.
Power Pack located their parents, but when the Technocrat's ship exploded, they were flung into space. Jack, who had recovered his original powers of mass and density, created a force field bubble around his family to protect them, and they were recovered by Friday.
The children, and their parents, recovered on New Kymellia. James and Margaret were still completely unaware of the existence of Power Pack and of their children's powers. Lord Yrik told them that he was still unable to remove the mental blocks that he had placed on Jim and Maggie's brains - meaning that they could never be told about the Pack without going mad (issues #44, #50). The Pack also discovered that they were unable to switch their powers around as they had done on the Technocrat's ship, so they were stuck with what they currently had. All the members of Power Pack had ended up with their original abilities: Alex with control over gravity; Julie with flight and acceleration; Jack with mass and density; and Katie with energy.
Friday transported Power Pack and their parents back to Earth, where they arrived at their New York City home just in time for Christmas.