Lights, camera, action!
We begin with a young woman reading a book by a man, who tells us of a time he was staying at the once-lavish and now rundown Grand Budapest Hotel.
At the hotel, he meets its mysterious owner: the once-richest man in all of Zubrowka, Zero Mustafa. Zero, who's a fan of the author's work, invites him to dinner, where he proceeds to tell the wild tale of how he came to be in possession of the Grand Budapest.
This is his story.
Then again, maybe it's actually the story of Zero's employer, one Gustave H. Gustave is the expert concierge of the hotel, and he expects the best of all the other employees. Zero is the new lobby boy, and Gustave gives him very strict, precise training so that he may live up to the standards of their marvelous hotel. We quickly learn that Gustave is an incredibly chivalrous man and enjoys entertaining elderly women in want of some attention.
One day, Zero finds that one of these women, Madame D., was found dead at her house, where Gustave and Zero immediately go. They find that Madame D. has left Gustave a very valuable painting, Boy with Apple, and her family is not pleased. Serge, the family butler, helps Gustave wrap the painting as he smuggles it out of the house, placing a letter in the back of the painting, unbeknownst to Gustave.
In not much time, the military police, led by Henckels, an old friend of Gustave's, show up and arrest Gustave for Madame D.'s murder (don't worry, you didn't miss anything: he's innocent). Zero, with the help of his girlfriend Agatha (who works at Mendl's pastry shop), smuggles digging tools into Gustave so that he and his new inmate friends can escape.
On the outside, the executor of Madame D.'s estate, Deputy Kavocs, is murdered by Jopling, a henchman that works for Dmitri, the not-very-nice son of the late Madame D., for not cooperating with the family's wishes.
Once out of jail, Zero and Gustave begin their search for Serge, who initially spoke against Gustave but whom they suspect was threatened into doing so by Jopling and Dmitri. After calling upon the Society of the Crossed Keys, a secret club of concierges, they make their way to a snowy monastery where monks direct them to a confession in which Serge awaits. He reveals that he was under pressure to speak out against Gustave (Jopling killed his sister when he went into hiding) and tells him of a second will that takes precedence in the event Madame D. was murdered.
However, Serge is strangled by Jopling before he can continue. Zero and Gustave chase Jopling down the mountain, eventually pushing him off a cliff. Henckels, who has been on Gustave's trail for a while, has finally caught up to him though, so they flee… right back to the Budapest. They're disguised as Mendl's employees and have Agatha infiltrate the hotel and smuggle out Boy with Apple, which is stored in a safe.
Then suddenly everything goes awry.
Dmitri shows up and hunts down Agatha to take his picture back and Gustave and Zero chase after Dmitri who opens fire on them, starting a spontaneous firefight between all soldiers currently being housed in the hotel. Henckels tries to calm everyone while Agatha, and shortly Zero, fall off the hotel, during which they see Serge's letter in the back of Boy with Apple as it hangs from a balcony.
Inside the Hotel, we see Henckels open the letter containing the secondary will which leaves everything (including the Budapest, which Madame D. owned) to Gustave. The rest is history. Not really. Zero and Agatha marry but Agatha and their infant son die from disease two years later. Gustave is shot when he stands up to soldiers. Zero, being Gustave's heir, becomes the owner of the Grand Budapest, which he keeps in remembrance of Agatha.
Then we zoom out through the lenses of our many frame narratives until we are again with (a) a girl reading a book from the (b) author who wrote the story that (c) Zero Mustafa told him, dining in the old, lonely hotel.