The reed goes on, the reed comes off. The reed rots and returns to the earth. The houses we work on outlast us. The thatch we use has never stood still. On The Roof is a thatcher's tale - a journey of discovery, and a reflection on what it means for a person or a building to belong in a place. It tells Tom Allan's story, leaving an office job in the city to find fulfilment among the Devon roofs, as well as the stories of six other people who share his trade. We meet the Hebridean son of a lobster fisherman who thatches with a dune-growing grass, a Syrian refugee who found peace among the seagrass roofs of a Danish island, and one of the first women to become master of Japan's 5,000-year-old craft of thatching. Thatching is an ancient, living tradition. To be a thatcher is to belong to a craft almost endless in its reach - at once one of the oldest ways of giving shelter, a way of working close to the land, and a deep immersion in the rhythms of a place on the most local scale possible: a village, a valley, an island. But the craft isn't frozen in time. Thatched roofs exist in a constant state of repair, renewal and alteration, and the trade is poised at a moment of profound change both in the way people thatch, and the plants they use to thatch with. As Allan reveals, the story of thatching is the story of our relationship with the land, and how we have chosen to treat it.