Timothy West and Prunella Scales have lived all their married life in London, but have never explored the canals on their doorstep. In this episode, they journey along the London Ring, as it's known to narrow-boaters, in a voyage of discovery through their home city. Starting in Brentford, they follow the Union Canal, and then the Regent's Canal, through the heart of the capital, until it meets the Thames at Limehouse. They meet up with Andrew Sachs and Sir Ian McKellen, and visit the cemetery at Kensal Green, and the grave of friend Harold Pinter. It's a tale of two cities: from the urban edge of Kentish Town, to the glorious grandeur of Regent's Park; from idyllic daylight moments, when they encounter nature and wildlife, to the darker night times when they become strangers in their own city.