"Gnoman Holiday" was an episode that appeared in Season 9 of the Smurfs cartoon show.
With the Smurfs visiting the period of the ancient Roman Empire, they find a nice quiet place out in the forest beyond the cities where they can assemble the time crystals in peace and quiet. They all feel so tuckered out from all the time-traveling they were doing, they're more than looking forward to a place where they could rest for a while. Smurfette rests herself near a waterfall, saying that if she sees another city, it would be too soon. Snappy, however, spots a miniature Roman city just on the other side of the water falls. But Papa Smurf isn't really concerned about cities or anything right now as he tells his little Smurfs that they should just take it easy and relax. Brainy takes this to mean that he can recite from his latest book that he's working on, but the other Smurfs tell him to put a sock on it.
Greatly offended by the response, Brainy starts to walk off, only to slip and knock Smurfette off her perch and into the aqueduct to be carried downstream into the miniature Roman city. Papa Smurf sees that Smurfette is in danger and is ready to dive in to save her, but Grandpa Smurf stops him from doing so, saying that he should stay and assemble the crystals, Then he and Hefty dive into the waterfall, with Snappy and Brainy following right after them.
Down in the Roman city, a group of young females of the people called the Gnomans are all lined up to enter Julius Geezer's temple so that his son Nerdo could pick which one of the nobles would be a suitable bride for him. Nerdo sits and looks rather disinterested at all the candidates that enter the throne room, rejecting each and every one of them. Julius Geezer demands that his son must marry before his sixth decade or else he will find a mate for his son. Then Ann the hairdresser comes into the room and tells the emperor that she is going on her lunch break. Nerdo is desiring to marry Ann, but his father says that he must marry a woman of stature. Geezer's adviser Sinus suggests that he should take a bath to calm his nerves, and as the emperor leaves the throne room, Nerdo sits alone and sulks.
In the royal bath house, Julius Geezer is ready to take a dip in the water when Smurfette comes pouring out of the fountain head, splashing the emperor and his adviser. Julius wonders who dares to soak him when he sees Smurfette emerge from the water all wet and comments that she must be a gift from the gods. Sinus takes note that, among her many beautiful assets, Smurfette is truly a "blue blood" in that she's all blue. Julius decides that he's going to make Smurfette his son's bride, which makes her react all negatively in saying that she's not marrying anyone. Sinus tells the maiden Smurf that what Julius Geezer says is not a proposal but a command, a thought that makes her somewhat fearful.
The bath house attendant is left picking up the towels when Hefty, Grandpa, and Snappy show up in the bath, wondering where they are now. The bath house attendant tells his guests that they're in the bath house of the Gnoman emperor Julius Geezer, and he would have the trespassers arrested and fed to the wild animals if they were discovered. Just as the three Smurfs say they are willing to leave as soon as possible, Brainy also shows up. Grandpa asks the bath house attendant if he's seen a blue female, and he tells Grandpa that she has been made fiancee of the emperor's son Nerdo and that she will be forced to marry him. Grandpa realizes that they will need to break up this wedding, so he asks the bath house attendant where Smurfette has been taken to. The bath house attendant whispers to Grandpa the direction of the door through which she was taken, and so Grandpa and the three other Smurfs begin their search.
In her own private room with Ann taking care of her beauty treatments, Smurfette is moaning that this is such an awful mess, and she's talking about the situation that she's currently in, not her hair. She couldn't believe that she's being forced to marry someone she doesn't even know. Ann says she could think of worse things than being married to the emperor's son, and that he's cute in a wimpy sort of way. Smurfette asks Ann why doesn't she marry Nerdo, and Ann tells Smurfette that Nerdo's father wouldn't allow it because she's just a hairdresser. Smurfette feels sorry for Nerdo being bullied around by his father just as much as she feels sorry for being in this mess. Ann sprays Smurfette with some perfume and tells her not to worry because she'll make an excellent bride for Nerdo, which is what makes Smurfette worried.
As Grandpa and the three Smurfs look through every door in order to find Smurfette, the royal guards carry her on a reclining litter into the throne room to be presented to her son as a prospective bride. Nerdo just looks at her in wonder, which Julius Geezer takes as acceptance and announces that there will be a royal wedding. Smurfette tells Geezer that where she comes from, Smurfs are free to do whatever they want, to which Geezer tells Smurfette that she should have stayed wherever she came from. Nerdo bravely agrees with Smurfette, saying that he should be free to marry whoever he wants, but Geezer refuses, telling his son that what he says is what will happen. Then Grandpa and the other three Smurfs show up in the throne room, demanding Geezer to let Smurfette go. Geezer responds by having the guards take the blue intruders to be fed to the Felions. This results in a big scuffle between the four Smurfs and the guards which ends with the Smurfs being carried away.
Smurfette didn't like to see her fellow Smurfs being fed to the Felions and so offers to marry Nerdo in exchange for their freedom. Julius Geezer accepts the offer and so has the guards release the Smurfs, ordering them to get her friends out of the city. Grandpa pleads unto Geezer that there must be something he and the Smurfs can do to win Smurfette back. Geezer declares that his decision is final, until Nerdo brings up "the edict", which Sinus explains that the betrothal may be challenged by having the challenger face the king's son in a test of strength. Geezer realizes that was his edict and asks the Smurfs if there's anyone among them who will challenge his son. Hefty says he's willing to do it, but Brainy inadvertently steps forward, claiming he can easily best Geezer's son, when he trips and falls before the throne. Geezer decides that Brainy will be the designated challenger, and Geezer says the contest will be set the following afternoon after the royal games. Hefty tries to get Brainy to relax, saying that the emperor's son would rather let Brainy win anyway. But as Brainy brags about how he's going to easily best Nerdo tomorrow, Geezer shows them who his real opponent will be -- a slobbering muscular brute named Biggus -- and after seeing him Brainy realizes that he's Smurf meat.
Off alone in the royal gardens, Smurfette is crying over being forced to marry Nerdo when she hears him speaking in an angry tone, sounding like he's finally standing up against his father. But when she goes over to see Nerdo, Smurfette sees that he's just talking to a bust of Julius Geezer with a crow sitting on its head. Nerdo tells Smurfette that if he says those things to his father, he'll get mad. He knows that this is a marriage that neither of them really want, but Gnoman law states that he must marry someone before his father's 60th birthday. As Smurfette asks Nerdo if there's someone that he wants to marry, Ann the hairdresser shows up, saying that she needs to get Nerdo ready for the big day tomorrow. Smurfette decides to leave the two of them alone so they could talk and get to know each other a little better, and as she watches from behind some shrubbery, she sees that Ann and Nerdo are a perfect match.
At the Gnoman Coliseum, Grandpa and the two Smurfs with him get front row seats to the match none of them -- or even Smurfette, who was sitting with Nerdo -- wanted to see: Biggus versus Brainy Smurf. At the drop of a napkin from the emperor himself, who refused to listen to whatever his son wanted to tell him, the big muscular brute started chasing Brainy around in the arena, with the bespectacled Smurf pleading for Smurfette to marry Nerdo to get him out of this fight. Grandpa tells Brainy to "use the net", and Brainy pulls out a net with which he hopes to use against Biggus, but instead he gets caught in it himself as he trips and falls. With Brainy held down on the ground by Biggus' foot as the brute is ready to give him the hammer, Nerdo interrupts his father's hand signal and gives the thumbs-up, causing Biggus to relent.
Despite not seeing the outcome he wanted, Julius Geezer tells his son that he finally won his bride. Smurfette refuses to let that happen and tells Geezer that his son wants to marry Ann. As Nerdo tries to speak for himself on the matter, Ann speaks up for him, saying that she wants to marry Nerdo. Geezer questions whether his son truly wants to marry "that servant", a comment that makes Ann react negatively by calling him a "bull head". Enraged, Geezer has Ann put into the arena where she will be fed to the animals. Nerdo watches fearfully at the scene below until he decides he has had enough and jumps down into the arena to save Ann from the hungry Felion. Ann is happy to see Nerdo being courageous enough to save her, and Julius Geezer is pleased to see his son being lively enough to rescue the servant he truly wants to marry and decides to let him do so. Smurfette is pleased to see that Nerdo and Ann will have a happy ending.
As the Smurfs leave the city of Gnome, they comment how glad they are how everything had worked out. Smurfette was thinking that she could have been the empress of Gnome, which makes Grandpa Smurf say that at least she will always be their queen.