There are 43 tidal islands around the UK, accessible just briefly each day, along beguiling and perilous paths.

As the tide retreats, five writers walk their favourite causeway to islands of refuge, pilgrimage, magic and glamour.

Patrick Gale joins those seemingly walking on water as they cross to St Michael’s Mount in this first episode. Between kite surfers and dog walkers, he is suspended between two worlds as he follows the S shaped causeway, shaped by relentless tides and currents. He is joined by Lord St Leven who tells him about the near impossible task of maintaining the route to the Mount, his family’s home since the 17th century. And from the tidal walk emerge the stories and myths that have built up around Karrek Loos yn Koos, first visited by Archangel Michael, and now by hundreds of thousands of tourists.

Across the series:

As sea levels rise and the sands shift, causeways are in flux. The Essayists draw us down onto the sands, revealing what these liminal routes mean to both them and the cultural history of the UK.

Producer: Sarah Bowen