During the summer vacation, the little girl Lena goes to visit her grandpa. Grandpa loves Lena very much but sometimes disappears down a rabbit hole with each stroke of his brush. Lena has no passion towards painting, and is not interested in the painting album that Grandpa sent as well. She feels a little bored.
One night, after grandpa falls asleep, Lena falls down her own hole into a hidden world of classical paintings. Guided by the fireflies flying out of the album, she gets on a moon boat. She sails through the Starry Night created by Van Gogh, and enters a fascinate world, the magic gallery, where the paintings are brought to life. She meets the gallery guard, and together they encounter collapsing Kandinsky, magical Monet and Da Vinci; they also help to capture an escaped ermine, play red-light-green-light with Mona Lisa.