Abstract: He is a brilliant maths professor, but the legacy of a traumatic head injury is only eighty minutes of short-term memory... Entrusted to take care of him is a young, sensitive housekeeper with a ten-year-old son. A beautiful relationship blossoms between them. The professor may not remember what he had for breakfast, but he devises maths riddles, based on her shoe size, or her birthday, revealing a poetic world to the housekeeper and her little boy. With each new equation, the three lost souls forge an affection more mysterious than imaginary numbers, and a bond that runs deeper than memory.