Walking along the crumbling defensive walls of Istanbul and talking to those he passes, Alexander Christie-Miller finds a distillation of the country's history, a mirror of its present, and a shadow of its future.

Caught between two seas and two continents, Istanbul lies at the centre of the most pressing challenges of our time. With environmental decay, rapacious development and tightening authoritarianism straining its social fabric to breaking point, it represents the precipitous moment civilizations around the world are currently facing.

In and around its crumbling Byzantine-era fortifications, Alexander Christie-Miller meets people who are experiencing the looming crisis and fighting back, sometimes triumphing despite the odds.

To the City seamlessly blends two narratives: the story of Turkey's tumultuous recent past told through the lives of those who live around the walls, and the story of Ottoman Sultan Mehmet II's siege and capture of the city in 1453. That event still looms large in Turkey, as Recep Tayyip Erdogan like a latter-day sultan invokes its memory as part of his effort to transform the country in an echo of its imperial past.

This is a meditation on the soul of Istanbul, a paean to its resilience and fortitude. Walk with Christie-Miller and see the danger, beauty and hope.