"The reason we went to England the first summer, the summer I was ten, lay in a long-ago promise. And a long-ago philosopher named Heracleitus.".

So begins the journey of Meggie Singh and her father, a charming, befuddled professor of philosophy from the Caribbean. Every summer Meggie and her parents leave New York City, and move to the home of Aunt Inez and Uncle Tom in England. There, Professor Singh struggles to write a book that takes on one of the greatest paradoxes to confound thinkers of the twentieth century: the dual nature of light as both particle and wave.

Each chapter in The Professor of Light is a summer spent in England as Meggie moves from childhood to the brink of adulthood and Professor Singh grooms his daughter in a rich mix of philosophy and Indian-Caribbean storytelling. Meggie adores her father, and the tales he passes down to her, which illuminate the lost history of her family scattered over India, Guyana, America, and England.

But Professor Singh is haunted by the past: a promise to his family in Guyana; tales of "the jumbee curse"; a mother who bound her daughters to herself with a red ribbon, and filled her son's pockets with letters, which turned to stones and brought him back home; the bird-ghosts who unleash their fury on those who dare to run away and seek out their dreams.