Louise is a flighty eleven-year-old who invents a thousand incredible stories. She was born in a French hospital via in vitro fertilization and has never known her father, which she is finding more and more difficult to accept.

Augustus is a model student who prefers books and silence. After the death of his mother, he has to follow his father from their native Romania to go and live in France.

Fate brings the two youngsters together and together they embark on a rather astonishing journey. Along the way they encounter a Roman (a real one), a lemon cake, a time traveler, policemen, a fairy and some lasagne. But above all, they find answers to the big questions, the questions that adults don't like to be asked.