A luminous and enthralling story of birds and science, ambition and sacrifice, revolutions - both big and small - and the late blooming of an unforgettable woman.

I first loved him because he taught me the flight of a bird. I was too young to realise that what I really yearned to know was why birds take flight - and why, sometimes, they refuse.

Meridian Wallace has lived through the Second World War, the atomic age, the Vietnam War and the dawn of the new millennium - yet she has always been torn between who she is and who circumstances demand her to be.

In 1941, spirited, ambitious and determined to prove worthy of the sacrifices her mother made for her, Meridian won a place at the University of Chicago to study ornithology. The last thing she expected was to fall in love with a man two decades older: her brilliant physics professor, Alden Whetstone - or for him to be recruited to Los Alamos, New Mexico, to take part in a mysterious wartime project.

When Meridian defers her plans to join him, she agrees to give Alden a year of her life. But this is a world, and a time, in which a wife cannot be a scientist and a woman cannot choose her own destiny. What begins as an electrifying intellectual partnership soon evolves into something quite different.

As the decades pass, Meridian strives to resist the clipping of her wings. It is a choice that will make her enemies and bring her heartache, but it also opens up unexpected possibilities: of freedom, and friendship and transformation...