NOTE: This spoiler was submitted by Spectre.
We open deep in the forest where a virgin maiden is about to be forcefully taken by an evil sorcerer who is planning to complete a ritual during the eclipse of the two moons. Just as he is about to complete his task, a group of knights crash the ritual and slaughter the sorcerer and his helpers. The lead knight tells the woman she is safe, the woman proclaims that she can only hope that in a hundred years time there could be a man as courageous as him.
Almost a hundred years later...
We find ourselves in the kingdom of the dwarfs where Prince Thadeous (Danny McBride) is about to hanged by the king for sleeping with one of his wives and his squire Courtney (Rasmus Hardiker) will be tarred and feathered. Thadeous tries to plead it wasn't as bad as the king thinks but to no avail. They drop the platform and Thadeous' feet touches the ground. Since they are dwarfs they only had a height appropriate gallows and thus Thadeous was too tall to die. He breaks off his restraints, grabs Courtney and they escape back to the kingdom.
His father King Tallious (Charles Dance) wants to know if he secured the smallest of quests; a treaty with the Kingdom of Dwarf people. Thadeous attempts to cover for himself saying they were ruthless people but his father sighs, having heard it all before. Just then his other more successful son Fabious (James Franco) comes back. Fabious had been off thwarting another plot of the sorcerer Leezar (Justin Theroux) and had killed his latest beast, a cyclops, collecting his severed head. Fabious also tells his father something else. He has found a bride, presenting Belladonna (Zooey Deschanel) a captive of Leezar. The king says they should all celebrate for this impending marriage. Thadeous is less than pleased that his brother has gotten all the attention.
At the dinner, Thadeous is sullen and unwilling to be happy for his brother. He keeps to himself and uses his squire Courtney to entertain him. An advisor to Fabious, Julie (Toby Jones) belittles Thadeous further, making him realize that the kingdom has never had a celebration for something good he did. Thadeous is saddened by this realization.
While the guests party, Thadeous goes off messing with a sword saying he is just as good as his brother. Fabious comes to talk to him. Thadeous says he doesn't like being second best and Fabious gets to have everything and be a king. Fabious tries to comfort him, and asks him to be his best man at his wedding the next day. Thadeous thinks it will be a boring affair, but Fabious says that the best man usually gets to sleep with the bridesmaids. Thadeous looks to his brother and says "You got a fucking deal."
However, the next morning it all goes wrong. Thadeous hears Boremont (Damian Lewis) rage that he wasn't chosen as the best man for Fabious' wedding. He calls Thadeous a joke, saying he is less than nothing. Deeply hurt, Thadeous runs off.
At the wedding, Fabious doesn't want to get marry without his brother, but eventually must go on without him. Fabious and Belladonna sing a song about their love.
Courtney comes to find Thadeous smoking with a sheep herder saying the wedding has begun. Thadeous will have none of it, saying he rather smoke with the man then be with people who think nothing of him. Courtney, a loyal servant stays with him.
Meanwhile, back at the wedding, Leezar crashes the party. He is mad that Fabious has killed all his creatures and dashed all his plots. Furthermore, he has stolen Belladonna, a virgin maiden he was saving for an important ritual. Fabious and the king try to protect Belladonna but Leezar is too strong, unable to be brought down with swords and able to use force magic to hurt them. Leezar kidnaps Belladonna.
Thadeous returns after a night of smoking having no clue what has happened. The king tells him Belladonna has been captured and now it is his time to show his worth. Thadeous can either go on the quest with his brother or be banished from the kingdom. Thadeous sighs, having no choice.
Thadeous, Fabious, Courtney, Boremont, Julie, and a bevy of other knights begin the quest. Their first stop is to see The Great Wize Wizard, a seer who can show them the way. Fabious and Thadeous go into the wizard's hut and find a small creature in a bed. The wizard asks for a kiss which Fabious and a reluctant Thadeous give. They are given a pipe with potent herbs to smoke in order to see what Leezar is up to. Fabious is freaking out by the herbs while Thadeous used to smoking similar stuff tells him to "Handle your shit, Fabious please."
The Wizard tells them Leezar plans to mate with Belladonna during the joining of the two moons. She will then give birth to a dragon, which was be the beginning of the end for the kingdom. They have five days before the eclipse and will need a sword made from Unicorn horns in order to kill Leezar, which they will need to find in a labyrinth. To get there, the Wizard gives them a special compass. Before they leave, the wizard asks them a riddle, which Thadeous correctly deduces that the wizard wants to be jerked off which they reluctantly do for the quest. They leave, disgusted.
Meanwhile, Belladonna wakes up in Leezar's castle, to see the face of Fabious, her love. Fabious begins to laugh and we see it is Leezar playing a cruel joke. Belladonna says she will be rescued but Leezar says she shouldn't get her hopes up because in five days she will be his.
The knights set up camp where they play a practical joke on Thadeous and convince him to eat a boar's heart. He goes into his tent angry at their cruelty.
Meanwhile, Julie is making a fire, which turns into a communications portal in which he can talk to his real boss, Leezar. Julie tells him what is going on, and Leezar order that Fabious be brought to him alive. As for Thadeous and his squire, they can be killed. Courtney sees the entire thing and runs to tell the brothers.
Fabious tries to make peace with his brother when Courtney tells them what they saw. They confront Julie, who tries to blind them and run off. Courtney grabs him and they discover that Julie has no genitalia. They take him back to the other knights and explain that Julie is a traitor working for Leezar. Boremont then shocks the brother's asking what Leezar's orders were. Fabious is shocked that his knights have sold the kingdom out, but Boremont says he was betrayed by Fabious. The knights go to kill the three, but they get away in horse driven carriage.
The evil knights give chase and try to board the carriage. Fabious ties a rope around the neck of one and throws him off to be dragged by the horses. Another attacks Thadeous and Courtney and they accidentally scalp him and push him out. Finally, two other bad knights try to board and Fabious says they have to get on the horses and ride away. The three get on the horses and Fabious breaks the ropes connecting them to the carriage causing it to flip with two knights inside.
Fabious sends the horses away as a distraction and wants to keep going. Thadeous wants to go home, arguing that he will most likely will die on this quest, and Courtney definitely will. Fabious tells them they are moving on.
Meanwhile, Julie is using one of the knights as a tracker to figure out where the brother's went. The knight says they went into the forest ruled by Marteetee. Julie laughs saying their quest to find them won't be that hard.
Thadeous, Courtney and Fabious are walking along when they see a naked forest nymph nearby. Thadeous says he will go "investigate" and tells the two to wait. Within a minute though, he realizes it is a trap and they surrounded and knocked out by a legion of naked women.
They are taken into a gladiatorial chamber along with three other prisoners. Marteetee tells them they will die. He unleashes his best warrior, a suave hugely muscled gladiator that quickly dispatches one of the prisoners. Fabious makes Thadeous promise to finish the quest if he dies then faces the man. Fabious shows his might and quickly kills the gladiator. Fabious then calls for their freedom but Marteetee denies this, instead calling for his honey pot. He sticks his hand in it and in the arena comes a snake monster in a shape of his hand.
Fabious tries to fight it, but is bitten. While Courtney is forced to suck out the poison, the monster kills another prisoner. Just as it looks to kill the remaining prisoners, the last prisoner chops off one the monsters heads, which makes Marteetee scream as he lost one his fingers in the process. The warrior begins to chop off more heads until Marteetee has only his middle finger. He screams for the warrior to reveal himself and is shocked when a woman shows herself. Isabel (Natalie Portman) says Marteetee had her village destroyed and she has come to kill him. Marteetee begins a speech, but Isabel just throws a spear and kills him. In the ensuing chaos, the four get away.
Fabious and Thadeous try to convince Isabel to come with them, at least until their paths have to diverge. Isabel agrees.
Later, Thadeous is peeping on the bathing Isabel. Fabious comes up and Thadeous says how beautiful she is and how he'd like to sleep with her since she is not like the easy women of the kingdom.
The four are eating at night, when Fabious and Courtney pretend to get firewood in order to give Thadeous alone time with Isabel. Isabel talks to him saying she's trying to avenge the death of her six brothers and parents. Thadeous tells her he can understand her pain, as his mother is dead. He explains their quest to kill Leezar and save Belladonna and the use of the compass to do it. Isabel listens, intrigued.
Fabious talks to Courtney, wondering if Thadeous is sleeping with Isabel at that moment. Courtney quickly says "no." Fabious confesses that he sometimes wishes he could be Thadeous as he has the entire kingdom on his shoulders; he's always expected to be perfect, well groomed, and off risking his life on quests. Courtney says he has it backwards; Thadeous envies him and wishes he could be more like his older brother. Fabious smiles.
The next morning, Fabious is shocked to find that Isabel has stolen the compass from Thadeous. After admitting that he told her about the quest, Fabious loses it. He is tired of his brother being unbecoming of his stature. He tells Thadeous he has thought highly of him despite his faults and that "You have the potential to be a noble warrior." Thadeous doesn't want to listen to it, saying being Fabious' brother is a curse, and he wishes he was not brothers with him. Fabious almost strikes him and says Thadeous is not to say another word.
The three continue onto Moulder's gate, their last stop before Leezar's castle. During the night, Fabious says he will go look for the sword and Thadeous can do whatever he wants. Fabious doesn't get far however before Boremont and the knights catch up to him and knock him out.
In a tavern, Thadeous and Courtney spot Isabel talking to some men. Thadeous confronts her about stealing the compass and finds out she is out to kill Leezar as well. Thadeous demands it back, but Isabel beats the crap out of him instead. Thadeous and Courtney are thrown out of the bar, but Courtney reveals he stole the compass back using his sleight of hand techniques he learned as a sex slave years back. They aim to return to Fabious and regain his favor, but find him captured.
Back in Leezar's castle, he is having dinner with the captive Belladonna and his three mothers who toast to "The Fuckening" that will happen in two days time.
The next morning, Thadeous wants to bail on the mission again. He doesn't get far, as Isabel finds them and wants the compass back. Thadeous counters that Fabious has been kidnapped and he needs to save his brother. Furthermore, since they both have the same endgame (to kill Leezar) they should join forces. Isabel agrees saying she relates to their desire to seek revenge against those who hurt their family, "and skin them alive as they scream." Isabel joins them while Thadeous whispers to Courtney that she is insane.
Using the compass they get to where they get to a dead end. However, there is a phrase written in a dwarf language. Courtney knows Thadeous can speak it so he looks at it and it translates to "What lead you there will lead you here." which he thinks is gibberish. Isabel finds a spot to place the compass and it opens the wall so they can journey into the labyrinth. They barely get in when they are confronted by a minotaur. The group separates in opposite directions.
Thadeous finds himself in a different room where he finds the sword they have been looking for. The keeper of the sword talks to him. Thadeous asks if he wasn't the right guy for the sword what would happen. The keeper says he would die. Thadeous offers to leave the sword and go home. The keeper shows him a world where Fabious is tortured and eventually killed and Thadeous is king, like he always wanted to be. If Thadeous truly wants that, all he has to do is leave. Thadeous pauses.
Meanwhile, Isabel finds the minotaur about to sexually assault Courtney. She pulls out a wood flute and begins a calming song to distract the minotaur. Just as it is calm, Thadeous shows up and spears it dead, to the shock of Courtney and Isabel. Thadeous shows them the sword, and says he came back for them. He tries to take a souvenir from the minotaur like his brother did for the cyclops. Finding out he cannot take a minotaurs horn, he settles for its penis, which he wears as a necklace.
Now ready to be a true knight, Thadeous begins to train and prepare himself to save his brother. He recruits a bar patron he had a fight with and the man joins them on the quest. They travel to the castle to kill Leezar.
As this is happening, Leezar has been torturing Fabious and explaining that he will have sex with Belladonna at the moment of the eclipse. Meanwhile, Fabious will be killed at the same time. Fabious pleads with Boremont to stop this, but Boremont says a regime change might be the right course of action.
The man Thadeous recruited takes the lead inside the castle. Almost immediately, he sets off a trap that impales and dismembers him. The remaining three realize they have to be way MORE careful.
They find Fabious and untie him. Thadeous tells his brother he could never abandon him or Belladonna and gives him the Unicorn sword. Fabious asks if he is the same brother that wouldn't show up as the best man at his wedding. Thadeous says he was not worthy of that honor. Fabious replies "You are now." They clasp hands in brotherly love and Isabel says they can finish their quest "when you maidens are done." The brothers smile and say "Done." They grab armaments and get ready for their final stand.
Leezar talks to his mothers, asking what he should do if Belladonna struggles. They reply they can take away her free will and make her want him. They cast a spell that makes her mad with lust. Just then, Thadeous, Fabious, Courtney, and Isabel break in. Leezar orders his men to kill them as he tries to finish the ceremony.
The heroes move up the spiral staircase, slaughtering any that get in their way. Isabel takes to fighting the three mothers. Fabious fights his former knights and Boremont. As for Thadeous and Courtney they join forces and kill Julie by throwing him off a large drop.
Meanwhile, Leezar, despite wanting to complete "The Fuckening" is freaked out by the transformed Belladonna and finds her repulsive now.
Isabel is surrounded by the three mothers, but is able to deflect their energy back onto them and kill them by decapitating them when they reformed into one body. She tries to kill Leezar but he uses magic to force her away. However, with the mother's death, Belladonna has come back to her senses.
Fabious kills the traitorous knights and finally Boremont. Boremont says he wishes it didn't ended like this. Fabious said he loved him knight to knight. Boremont said he loved Fabious as a man loves a man (he's gay). Fabious says "oh" as Boremont dies.
Thadeous goes to free Belladonna, telling her they are here to save her. Leezar, though not completing the ritual, gets new powers during the eclipse which turn him into half man, half dragon. He rises up to kill them all. Thadeous holds his ground in protecting Belladonna saying, "If you want to fuck her, you going to have to fuck me first." Leezar replies that is no problem. As he goes in to strike, Fabious comes up behind him saying this is his last evil scheme. Leezar scoffs saying he cannot be killed by swords of mortal man, Fabious says, "I know." and shows the unicorn sword. Fabious stabs him and Leezar burns away to ash. Fabious and Belladonna embrace.
As the group is about to return to the kingdom they offer to take Isabel there so she can have a vacation from questing. She declines, saying she has to find a band of thieves "and set them on fire individually." Isabel says she will miss Thadeous and gives him a kiss goodbye. Thadeous sheds a single tear as she leaves (mirroring a story his brother told him about his love for Belladonna) and the group departs for home.
They return to a thunderous welcome by the people. Belladonna asks if they are cheering for Fabious. Fabious replies they are cheering for all of them. "Even me?" Thadeous asks. "Especially you, brother." Fabious says, proudly. Thadeous pumps his fist in victory.
Fabious and Belladonna get married and have a happy wedding. Thadeous talks to his father, who tells him he is proud of his son for saving the world on his first quest. Thadeous is less than modest, saying Fabious helped when he could. The king just smiles, both of his sons now heroes.
After the wedding, Thadeous is in his room trying to get some "alone" time. His brother comes in and tells him he found his pet lizard he lost at the beginning of their quest. Thadeous thanks him for his thoughtfulness. After his brother leaves he goes to resume when a figure enters his room. It is Isabel who finished her latest quest quicker than expected. Isabel said she couldn't stop thinking about him and Thadeous echoes the sentiments. They begin to passionately make out.
Isabel stops before things get too heated and explains something important. She removes her clothing to show she has been cursed with a steel chastity belt by an evil witch. They would have to go a quest to kill her in order to make it fall off. Thadeous then confirms that they would have to go a dangerous quest just so they could have sex. Isabel offers to go alone but Thadeous says he will go with her. It's just that he just wanted to have some time at home for leisure. Isabel suggests they could do some other things but Thadeous stops her saying, "Fuck it. Let's kill the bitch."