Christmas again? Where did the time go? Mr. Mxyzptlk, an imp from the fifth dimension makes every day Santa's day.
Lois and Clark are preparing for their Christmas with their family and friends in their new home. Clark tries to get Lois to stop looking at Christmas as just a hard chore and start feeling the magic of the season.
Suddenly a Imp from the fifth dimension named Mr. Mxyzptlk appears after breaking through an inter-dimensional vortex. He is determined not return this time and stay to rule the third dimension and knows that Superman is the only one capable of stopping him.
He finally meets Clark on Christmas Eve in the elevator as he heads back to Daily Planet after saving someone and introduces himself.
After Clark leaves the elevator, he finds that time has gone backwards four hours to when he and Lois first arrived at the Daily Planet and the day keeps repeating itself whenever the clock reaches four. Mxyzptlk appears and tells him that he has trapped Metropolis in a time loop to get rid of hope. Every time the day repeats itself, people lose a little bit of hope eventually making Superman, who is the only one outside it, useless to them.
The loop continues and people's attitudes keep changing as well as the newsroom Christmas Tree that keeps getting smaller and smaller. Clark's father is the first to die from loss of hope. An angry Clark confronts Mxyzptlk and demands for them to be set free. The Imp makes a deal with the Man of Steel saying he will restore hope to the people if he agrees to leave Earth forever and allow him to rule.
Clark refuses and his hope breaks Lois free from the loop as well. The loop begins again and Clark and Lois work together to bring hope to the gloomy people. Mxyzptlk appears again, astounded by how delighted everyone is, but tells Superman that this will never break the loop and he will still be ruler of this dimension.
Lois then appears with a present sent to him. Mxyzptlk is taken aback and excited as no one had ever given him a present before, but when he reads the gift card to see who it's from, he unintenionally says his name backwards "Kltpzyxm", which has always been the only way to send him back. He realises too late that he has been tricked and disappears back to his own dimension.
Afterwards the small tree suddenly grows back to it's enormous size and the loop is broken forever. Lois at last sees the magic of Christmas and the people of Metropolis finally get to enjoy their Christmas with each other.