The book describes the story of Hannie de Vos, who lived for many years with her children on a sheep farm on the Sophiapolder — a small island in the river Noord, about twenty kilometres from Rotterdam. The family was forced to leave their home because the island would soon become a fresh-water tidal marsh. The area of Sophiapolder is destined to become new nature, or a so-called “Delta Nature”.

“I have difficulty with the idea that humans are superior and can construct nature. Should you really manipulate nature, or design it the way you see fit? Because in order to do that, you have to remove something valuable as well.” Hannie de Vos, speaking about this project of re-wilding (“The Sophiapolder: Farewell in Five Acts”, from A Falling Horizon, Act 4, p. 159)

A Falling Horizon is a compact book with a clothbound hardcover, and a small tipped-in photograph. The print is dislocated from its original place, to underline the meaning of the title — a falling horizon, a falling perspective of something destined to disappear. The first pages in the book confirm this feeling of unsteadiness. Hannie de Vos and her children’s house will soon disappear, and all the spaces of Sophiapolder will be redesigned. They will no longer exist as the photographer saw them. Opening the book, after the title page, from page number 2 to page number 6, images fade in the paper, they seem bleached, untouchable. Only after this quick vanishing introduction do we get to enter into the story. The text by Tracy Metz divides the narration in five parts: The Last Farmer; The Other Side; Delta Nature; Cultural Landscape or Wilderness; Farewell.

At certain points the disappearing effect returns throughout the book, reminding us of the sad condition of Hannie de Vos’s family, deprived of its own story and land.

Heidi de Gier closely followed the family and the island's changes for a year, and her photographic story is both a documentation of a place that soon will be completely different, and an intimate-emotional story of a family that wants to live according to nature, respecting the natural system without reshaping it. At the end of the book we can find a few farewell images, especially foggy landscapes. They echo some of Hannie de Vos's questions: are humans allowed to manipulate nature or design it?; is nature (artificially) re-design-able?; is it necessary to do so, ignoring individual stories, like the one of Hannie de Vos’s family?

Heidi de Gier was able to fix the last moments of the de Vos’s family, but their past will soon become just a memory.