A young woman walks into a cemetery in the Republic of Zubrowka, a place said to have fallen on hard times. She passes a bench with three men singing and then approaches a memorial with several hotel keys attached to it, dedicated to a man known only as Author. The woman puts a key on the memorial and then takes out a book titled "The Grand Budapest Hotel".
1985 - We meet the Author (Tom Wilkinson) in his home as his grandson runs around firing his toy gun. The Author addresses the audience and begins to tell the story behind his book as it was told to him in a very unexpected way.
1968 - In his youth, the Author (here played by Jude Law) travels to Zubrowka, a place that has been devastated by war. He ventures up to The Grand Budapest Hotel, which was once well-renowned. It sees very few guests apart from the Author. He chats up the young concierge M. Jean (Jason Schwartzman). They see an old man (F. Murray Abraham) sitting in the lobby by himself, looking rather sad and lonely. The Author asks M. Jean who this man is, and the concierge appears surprised that the Author does not recognize him. After a moment, the Author realizes he is Zero Moustafa, the owner of the hotel. The two of them discuss why he has chosen not to close the hotel down despite its financial troubles. The moment is interrupted when M. Jean has to run to a man who is choking. The Author retreats in an elevator.
The Author takes a bath and meets Zero there. He invites the Author to dine with him that evening. When they meet again, Zero begins to tell his story.
Part 1 - M. Gustave
1932 - When he was a teenager, Zero (here played by Tony Revolori) began working as a lobby boy at the hotel under the supervision of the legendary concierge, M. Gustave H. (Ralph Fiennes) Gustave orders his employees to set up a dinner in his suite. Everybody works at a rapid pace without skipping a beat. Gustave shares a meal with the elderly dowager countess Madame D. (Tilda Swinton) The old woman tells Gustave that she fears this may be the last time they see each other. She believes that somebody may be conspiring around her. After their dinner, Gustave sends her away in his personal car. The two of them reaffirm their love for each other before she leaves. Gustave then orders Zero to fetch a candle to light in honor of Madame D., yet he does not recall ever seeing Zero around and is unaware that he was recently hired. Gustave initiates an impromptu interview with Zero. Despite what Zero begins telling him, Gustave determines that the boy has no hotel experience, education, or family. When asked why he would want to be a lobby boy, Zero replies, "Who wouldn't, at the Grand Budapest Hotel?" Gustave is pleased with this answer. Zero asks him if he was ever a lobby boy. Gustave merely replies, "What do you think?"
With Gustave acting as his mentor, Zero works at the hotel just as quickly and efficiently as everybody else. He never misses any detail to ensure the guests are perfectly pleased with their visit. The identity of the hotel's owner is a mystery, but he sends his emissary, Deputy Kovacs (Jeff Goldblum) to the hotel to check up on business. Zero also learns that many of the hotel's most special guests would come for Gustave. It became well-known that the man would sleep with a number of elderly blonde women with insecurities and a need for attention. During this time, Zero would come to meet the love of his life, Agatha (Saoirse Ronan), a baker with a distinctive birthmark on her cheek who works at Mendl's, Gustave's favorite pastry shop. However, Old Zero doesn't want to discuss Agatha with the Author.
Part 2 - Madame C.V.D.u.T
While fetching newspapers, an article catches Zero's eye. He rushes back to the hotel to show Gustave. Madame D. has been found dead in her bathroom. A shocked Gustave immediately takes Zero on a train where they travel to Madame D.'s estate. On the train, they stop by a barley field on a day that is known as the "Closing of the Frontier". Gustave and Zero see soldiers standing in the field. A group of soldiers enter and ask to see the documents of both men. Gustave shows his papers, but Zero has none as he is an immigrant. The main soldier orders Zero to come with him. Gustave defends Zero and gets into a fight with the soldiers. They pin the two of them against the wall, and Gustave, seeing Zero in trouble, barks at the soldiers, "TAKE YOUR HANDS OFF MY LOBBY BOY!" Entering the train car is Inspector Henckels (Edward Norton). He recognizes Gustave since he and his parents were guests at the hotel, and Gustave in turn recognizes Henckels as "Little Albert". Henckels gives Zero a pardon for the trip, but urges him to get official papers immediately.
Gustave and Zero arrive at Madame D.'s mansion. Her maid, Clotilde (Lea Seydoux), guides them to the old woman's body lying in a casket. Gustave speaks to her, admiring her skin and saying she looks as lovely now as she did in life. He kisses her, and Clotilde tells Gustave that the butler, M. Serge X. (Mathieu Amalric), wishes to speak to him. Serge is frantic and panicky. They walk into Madame D.'s wake, where Kovacs is acting as the executor of her estate. Sitting there, expecting some sort of inheritance are Madame D.'s ungrateful offspring - her son Dmitri (Adrien Brody) and his three sisters, Marguerite (Michaela Caspar), Laetizia (Sabine Urig), and Carolina (Heike Hanold-Lynch). Kovacs reads her will to everyone, which states that she bequeathed to Gustave a valuable and cherished painting, "Boy With Apple". Gustave is taken aback while Dmitri is enraged. One person asks who Gustave H. is, prompting the man to introduce himself to everybody. Dmitri walks over to him while hurling homophobic slurs. He threatens Gustave if he finds out that he happened to lay a finger on his mother, alive or dead, to which Gustave replies that he goes to bed with all his friends. Dmitri punches him in the face. Zero punches Dmitri in the face, and in turn, Zero is punched by Dmitri's ruthless right-hand man, J.G. Jopling (Willem Dafoe).
Gustave takes Zero to the room where "Boy With Apple" is hanging. It is the only thing in Madame D.'s possession that Gustave truly admires. With Zero's help, they take it down and replace it with a vulgar painting called "Two Lesbians Masturbating." Gustave has Serge wrap up "Boy With Apple". Serge sticks an envelope labeled "CONFIDENTIAL" in the back of the painting. Gustave and Zero leave immediately.
On the train ride back, Gustave realizes that Dmitri may come looking for the painting. He proposes to Zero that they sell off "Boy With Apple" on the black market, and, in exchange for his services, Zero will be given 1.5% of the cut and Gustave will make him his heir. Zero agrees.
Back at the hotel, Gustave and Zero see Henckels and his soldiers arriving at the front of the hotel. Henckels tells Gustave that Madame D. was murdered with poison and he is being arrested as a suspect. Gustave quickly runs away with the soldiers chasing after him.
Part 3 - Check Point 19 - Criminal-Interment Camp
One week before his trial, Gustave is imprisoned. Zero goes to visit him and sees Gustave's face sporting two black eyes and a bandage. He explains to Zero that he beat up an inmate named Pinky Bandinski after he questioned Gustave's virility. He made a point to prove himself and earn trust and respect from the other inmates immediately. Zero tells him that there was one other suspect in Madame D.'s murder - M. Serge X. Unfortunately, he has fled.
Jopling is seen visiting Serge's sister, who is described as being club-footed. She denies having seen her brother recently and she is visibly frightened by Jopling. He tells her to get Serge back home soon.
In his absence, Gustave gives Zero a letter to read to the hotel employees to remind them to continue their hard work and sending love to them, as well as instructing them to tell Zero if anything should be out of place.
Gustave continues to gain allies in prison as he serves them mush that he made. One large inmate with a scar on his face is particularly fond of it. He then goes into a cell with inmates Pinky (Florian Lukas), Wolf (Karl Markovics), Gunther (Volker Michalowski), and Ludwig (Harvey Keitel). Gustave shares with them his favorite pastry from Mendl's. Together, they plan a break-out from the prison with a design drawn up by Ludwig. The only tool in their arsenal is a "throat slitter" (a straight razor), and Gustave looks at the Mendl's box, hatching an idea.
It is at this point where Old Zero becomes overwhelmed with emotions and he starts to cry. He explains to the Author that talking about Agatha makes him emotional. When they were young, he and Agatha saw each other after his frequent trips to Mendl's to pick up the pastries that she baked. They were very much in love, and Gustave also took a liking to the girl. Her part in the break-out was that she baked pastries with tools inside them. When the prison guard cuts up the food to check for any contraband items, he does not bother with the pastries, allowing the tools to slip by him. Zero gives her a code and key to find the safe where he and Gustave hid "Boy With Apple", though she is not keen on participating in the transfer of a stolen painting.
Dmitri and his sisters, along with Jopling, meet with Kovacs to discuss the whereabouts of "Boy With Apple". Realizing they are going to leave empty-handed and with no knowledge of how it got taken, Dmitri storms off. Jopling tosses Kovacs's cat out the window where it hits the ground and dies. Later, Kovacs collects the cat's body and boards a trolley. Jopling follows him close-by on his motorcycle. Kovacs arrives at the Kunst Museum 15 minutes before closing time. When he is alone, he sees Jopling's bike outside. He turns around to find Jopling behind him. He slams the door on Kovacs's fingers, severing four of them, and Jopling murders him.
Gustave and the inmates begin their plan of action to escape. After having used their tools to dig a hole, they travel through the prison to break out. One inmate sees this and tries to rat them out, but his cellmate, the scar-faced man that liked Gustave's mush, subdues him (probably kills him) to allow the men to continue their escape. They evade the guards until they open a hatch to find five guards playing poker. Gunther jumps in with his knife and stabs all of them to death, but he too is killed in the process. Finally, the remaining men reach the outside of the prison with Zero waiting for Gustave. Ludwig, Pinky, and Wolf retreat in their own getaway car after bidding farewell to Gustave and Zero. Gustave asks Zero if he brought him any spare clothes or his favorite cologne, which Zero didn't. Gustave angrily berates Zero for his failure to do so and asks him why he would bother having traveled to this part of the world to look for work. Zero tells Gustave that his family was killed when war broke out in his homeland, forcing him to retreat and look for work on his own. Ashamed of his words, Gustave sincerely apologizes to Zero and hugs him. He asks Zero about Agatha. Zero starts to recite a lovely poem until the sirens go off, forcing them to run.
Agatha decides to look for "Boy With Apple" without her boss finding out that she's left. Footsteps are heard approaching her room. The scene cuts to Henckels reading a newspaper with the headline, "LOCAL GIRL'S HEAD FOUND IN LAUNDRY BASKET". Henckels is told they found the laundry basket and asks for it to be brought in. He pulls out the severed head of Serge's sister, who was once again visited by Jopling.
Part 4 - The Society of the Crossed Keys
Gustave sends a call to his friend and fellow hotel concierge, M. Ivan (Bill Murray). Ivan makes a call to the other concierges and they form a group to come up with a way to help Gustave and Zero. The concierges - M. Martin (Bob Balaban), M. Robin (Fisher Stevens), M. Georges (Wallace Wolodarsky), and M. Dino (Waris Ahluwalia) - all drop their tasks and have their lobby boys stand in for them as they figure out how to help Gustave. Ivan pulls up in a car and picks up Gustave and Zero. He even brought Gustave's favorite cologne.
Gustave and Zero are taken to a ski resort. They ride a lift and travel to a monastery where the monks direct the two of them to the confessional booth. Waiting for them there is Serge. He confesses to Gustave that he was forced to flee after being threatened, and he knows that his sister was murdered. Serge also tells Gustave and Zero that Madame D. wrote up another will in the event of her murder. It was burned, but he secured a copy. Before he can continue, the confessional window is closed, and it is silent. Gustave and Zero run out and open the back of the booth to find that Serge has been strangled to death. They spot Jopling and chase after him. Jopling escapes on skis while Gustave and Zero hop on a sled. Zero steers the sled to chase Jopling, leading them to crash near a cliff. Zero is deep in the snow with his feet sticking out while Gustave is hanging over the edge of a cliff. Jopling stomps on the ice to break the cliff and kill Gustave, but Zero emerges and shoves Jopling off the cliff to his death. He rescues Gustave but they are forced to run again when they are spotted by Henckels.
Part 5 - The Second Copy of the Second Will
The hotel is now under the command of M. Chuck (Owen Wilson) while the military surrounds the place should they spot Gustave. Agatha gets into the hotel by delivering pastries from Mendl's with the intent to find "Boy With Apple". She finds the safe and opens it to retrieve the painting. Dmitri and his sisters arrive at the hotel, and he spots Agatha holding the painting. He follows her to the elevator. Meanwhile, Gustave and Zero sneak in under the guise of delivery men from Mendl's as well. Dmitri tears open the wrapping to confirm that Agatha is holding "Boy With Apple", but he loses her on the sixth floor. He spots Gustave and Zero coming out of the elevator, and he pulls out his gun to shoot at them. The other hotel employees pull out their guns to start a shootout until Henckels runs in and orders them to stop. A crash and scream are heard amidst the silence. Zero knows it's Agatha and he runs after her. He finds her dangling from a balcony with the painting hanging over the edge. He runs over to try and save her but they both fall and land in the Mendl's truck, with the pastry boxes breaking their fall. They embrace and she tells him that there is something in the back of the painting.
The envelope from Serge is opened and read - Gustave is vindicated of Madame D.'s murder and is left with not only "Boy With Apple", but with a large portion of her fortune. The business at the hotel prospers, and Gustave continues to court older women and he names Zero his successor. Dmitri is later reported to have disappeared without a trace.
As Old Zero continues the story, he notes that Gustave and Agatha did not live to grow old. Although he and Agatha married, with Gustave officiating the wedding, she and their infant son died two years later after falling victim to a fatal disease. Old Zero also tells the Author of his last day with Gustave - the two of them and Agatha were traveling on the train. He answers Zero's question of if he was ever a lobby boy, and he says yes, but Zero was a much better lobby boy than he ever was. The train stops at a barley field again, on a day described as "The Start of the Lutz Blitz". Enemy soldiers enter the train to ask the men for their papers again. Gustave gives the main soldier the pass that Henckels gave Zero earlier, but the soldier tears it up. He hits Zero in the face with the butt of his gun, sending Gustave into a rage where he attacks the soldiers. Old Zero states that Gustave was later shot for this.
With his story finished, the Author asks Zero if he chose not to sell the hotel to maintain a part of Gustave's world. Zero replies he kept the hotel as a tribute to Agatha and the best years of his life. He believes the world Gustave had was gone before he worked at the hotel. He departs from the Author. The Author states that he would later travel to South America after visiting the hotel, which he describes as "marvelous ruins that he never returned to."
The film closes with a shot of the young woman finishing the Author's book at the cemetery.