Oscar, a ten-year-old boy suffering from leukaemia, spends the final twelve days of his life in hospital. Although no one has the courage to tell him directly, Oscar knows he is going to die, and his struggle against the world breaks out with innocence, passion, and despair.

The only person he truly connects with is the Lady in Pink, an elderly nurse with an unmatched talent for inventing imaginative tales and imparting life lessons. She encourages Oscar to live each day as though it were ten years long, and teaches him to write letters to God to help ease his loneliness.

These letters, written in a humorous, childlike style, are far from naive. Beneath the playful language lies deep emotion, and pain seeps through the lines. The entire story is a whirlwind of conflicting emotions: rebellion and acceptance, regret, love, hope, sorrow, anger, and ultimately, understanding.

While these feelings often play out through the people around Oscar, the true addressee of it all is fate itself.