What Happened To Us

It ended on a Tuesday, over takeout they didn't finish.

The way things usually end now. No fight. No betrayal. Just a good man in her doorway saying: "Nothing happened. I just don't feel it anymore, and I don't know why."

Sia debugs code for a living, and she cannot get over the fact that her own love story ended with no known root cause. So she goes looking. Not for why they ended, but for why love ends at all.

From rain-soaked Seattle streets to snow-covered peaks, from glittering parties to ancient monasteries, from Hollywood mansions to the ruins of Greece — she follows the question, searching for what makes relationships begin, fade, and last.

What she brings home is far bigger than any answer: an engineer’s framework for modern love, assembled piece by piece and ultimately delivered on a stage before a thousand women. In the crowd, the two men she loved are waiting for an answer of their own.

Part love story, part reverse-engineering of the modern heart. For anyone who has ever wondered why love feels thinner and relationships seem harder, this book offers something rarer than a happy ending: an explanation.

Every heartbreak has a root cause. It’s time you found yours.