When a young man's girlfriend mysteriously disappears, his heart breaks. Determined to find the imaginary city where he suspects his beloved has settled, he embarks on a lifelong search that leads him to a strange city with its own rules and on a journey between the real world and another world. There, people have no shadows, unicorns roam, and willows grow.

He finds his girlfriend working in a different library – a library of dreams. She remembers nothing of their shared life. As the seasons pass and the man struggles to discern the fluid boundaries between the two worlds, he is called to decide what he is willing to lose.