The episode starts inside Santa's building, which explodes because Quillgin shoots the lock with a gun, and he is shown with a present, running towards Santa's sleigh. He then flies off to the outer limits of the North Pole and is about to open the box, but something crashes against the sleigh. Santa comes flying in with a floating snowboard and takes the present away from Quillgin. They fight in the sled for awhile, but Quillgin pushes Santa to the wall and starts to open the box again. Santa yells a command to Rudolph, his lead reindeer, who shoots Quillgin with a laser from his red nose, stopping him for a second. Santa then takes the box and jumps onto the edge of the sleigh. Unfortunately, Quillgin shoots Santa and he falls out of the sleigh, taking the box with him.
Meanwhile, there is a Christmas party going on at the park house. Muscle Man is smashing cookies, and Pops is busy taking some candy canes off the tree. Audrey comments that Benson's sweater should be the winner for "Ugliest Sweater", and Benson nervously excuses himself to get some soda. Meanwhile, Mordecai and Rigby are doing a skit over the phone for Margaret, who is at her parents' house. Mr. Maellard leaves quickly while Benson's about to get some soda, saying that he needed to attend six more parties and again that his sweater is terrible. Benson tells Thomas to get some more soda from Skips's garage. But Thomas' head has gotten stuck between the stair rails and can't get out, so Mordecai and Rigby volunteer.
Mordecai and Rigby go to the garage when Mordecai sees something fall in there. They quickly go inside, and see an injured Santa telling them to take the box. Rigby starts to open the box, but Santa quickly tells him to stop, saying they must destroy it. The two initially doubt it when he tells them that he's Santa Claus, but when Santa says that they wrote to him ever since they were kids, the two believe him. When asked why the box must be destroyed, he explains that a few months ago, Quillgin suggested a present box that would grant anything the person desired. Santa did not know that dark magic was used, but when a testing family used it, they turned evil and the box had to be locked up. Now Quillgin is chasing after the box to get revenge.
Mordecai and Rigby lead everyone back to the garage a few minutes later, but Santa is gone. Everyone thinks that it was a prank but the park workers start fighting for the box after Benson opens it up. Muscle Man tries to break the box with a huge hammer, but the hammer explodes upon contact. Skips states that the box is made by a dark magic and the only way to get rid of it was to push it in into lava.
An abandoned mineshaft in East Pines is the closest place where lava is, so the park workers start to quietly go through the snow. But Rigby wants to "fix their snowman's nose" before going, and he moves the carrot. An alarm goes off, and the East Pine workers capture them. Meanwhile, Quillgin arrives in Skips' garage and knows that the box was there. They move out and towards where the workers are.
Benson explains to Gene, the boss, why they were here, but Gene doesn't believe him, thinking that Benson was mad that someone got him "a horrible sweater for Christmas." He takes the box away from them and tells another worker to open it. The East Pines workers start fighting for the box after opening, and Mordecai gets the box back. The security cameras start beeping after, and Quillgin is shown entering the park and beating up the guards. The park workers start to beg Gene to let them go, but the door starts to bang open. Rigby yells that it's too late, but fortunately, it was an East Pines worker with some eggnog, who tells them that a creepy elf is trying to break in. Gene, finally believing them, leads the park workers to the abandoned mineshaft, warning them about the booby traps.
They go in and are greeted by a dead end, which turns out to be a slide. Everyone stumbles to the ground for a second, and Mordecai starts to keep moving on, but a skeleton is right in his face. It was a skeleton above some press-able tiles, with two icicles jabbing through it. Benson steps on a tile, and a sharp icicle almost slays him. There are some instructions written on the wall, saying that one step on the correct tiles, and they will be killed if they make one wrong step. Mordecai starts to use the skeleton, but it falls to the ground. Then Muscle Man volunteers to push the tiles. He starts to press the tiles in some strange dancing fashion, and completes the trap. There is another slide, and everyone goes down it. At the same time, Quillgin is looking at the workers with the spy cameras back in Gene's office.
The second booby trap is a pinball machine game. The instructions say that if one racks up enough points, a bridge will grow, but if they miss a ball, a part of the ground will break down. Benson does this one, and starts to quickly get points. He misses one ball, and Muscle Man almost falls down. Quillgin interrupts everyone, and chases them. Everyone run across the bridge, and Benson barely makes it in time before the bridge drops. Some of Quillgin's henchmen fall down instead, but Quillgin himself is still alive.
The final trial is wrestling a polar bear. Pops gladly steps in to wrestle the bear. He seems at a disadvantage, but he quickly beats the bear, pinning him onto the ground. The bear stands up again, congratulating them for finishing the last test, and a portal opens up in his belly, signaling them to go in. The slide leads them to the lava pit. But before Mordecai can drop the box into the pit, Quillgin (who got there by taking the stairs) steps out from the smoke and points a gun at them. Mordecai is about to hand over the box, but something takes Quillgin's gun away and throws it to the lava pit. It is Santa, who was using the invisibility cloak. Santa wasn't actually hurt when he got shot thanks to his bulletproof clothes; he just got stunned for a bit. Angry, Quilgin throws a grenade at them, and the park workers are separated from the box. Quillgin takes it, and wishes that Christmas will be destroyed forever. A red button appears in the box, which would explode the whole Earth and everything that has Christmas in it. Mordecai charges and tackles Quillgin, both getting sent into the lava. Rigby quickly follows them in. While they are falling into it, Mordecai, Rigby and Quillgin are fighting to get the box back. Mordecai is able to get the box and wish for floating snowboards, and the two friends escape the lava. Quillgin gets hold of the button, but he falls into the lava before he could push it, along with the present box.
They all leave the mine and arrive home with a ride from Santa's sleigh. They each say bye to him, with Santa telling Benson that he should have thrown his sweater into the lava pit. Santa thanks Mordecai and Rigby, and leaves with his famous "Ho ho ho!" Back in the house, Benson startles Thomas, freeing his head, and then tells Mordecai and Rigby to clean everything up. He leaves to get the cleaning supplies, but there is a present under the tree for Mordecai and Rigby. It is an invisibility cloak, and the duo play video games after Benson can't find them.
The episode made its home video debut on the Cartoon Network Holiday Collection, released on October 7, 2014.
Hi Five Ghost
|Roger Craig Smith|| Thomas|
|Ed Asner||Santa Claus|
|Thomas Haden Church||Quillgin|
|Kurtwood Smith||Gene the Vending Machine|
|David Ogden Stiers||Mr. Maellard|
|Cartoon Network Studios|
|"A Space Ghost Christmas" • "George and Junior's Christmas Spectacular" • "Dexter Vs. Santa's Claws" • "Twas the Night" • "Happy Baboon Holidays" • "Fa-La-La-La-Ed" • "A Johnny Bravo Christmas" • The Powerpuff Girls: Twas the Fight Before Christmas • "Christmas Con Carne" • Ed, Edd n Eddy's Jingle Jingle Jangle • "Christmas Evil" • Billy & Mandy Save Christmas • "A Lost Claus" • "Operation: N.A.U.G.H.T.Y." • "Have Yourself a Joyful Little Animas" • "Kamp Kringle" • "Merry Christmas" • "The Class of 3000 Christmas Special" • "Hey, Hey It's Knishmas!" • "Low Tidings" • "Holly Jolly Secrets" • "The Regular Show Christmas Special" • "Christmas" • "Uncle Grandpa Christmas Special" • "Merry Christmas Mordecai" • "Secret Santa" • "Merry Moochmas" • "Christmas Parties" • "Christmas in Space"|