In the darkness of winter on the first day of the year, a woman in Copenhagen is making a list. She plans to set out and see all of Denmark's butterfly species in a single year. She knows nothing about butterflies. She doesn't even know why she wants to see them. She just knows that something is calling her. The pull is irresistible. The Butterfly Season tells the story of what happened next. We follow Lea Korsgaard as her list takes her to landscapes she never knew existed, shaped by the wind and by the sea.

She walks on ancient seabeds and hills made of algae shells. She is led to secret places by strangers who offer their help along the way. And she is led into the past; into the lives of her ancestors, and into the world of books, philosophy and mythology. Because ever since humans started thinking about the meaning of life and death, the butterfly has symbolized our hope of rebirth--and confronted us with the biggest questions of existence: Why do we live? And what are we living for?.