Michael Portillo resumes his exhilarating tour of San Francisco to find that diversity has been at the heart of the city since the days of the gold rush, though not always harmoniously so. Following his Appleton's guide, Michael heads to Chinatown to hear of the huge contribution Chinese immigrants made to the economy, working as miners and building the transcontinental railroad. He discovers an entrepreneurial community who overcame discrimination laid down by the law, and finds that fortune favours the brave with iconic Chinese treats created in America!

Michael Portillo's thousand-mile rail journey through California continues south toward Santa Clara in the heart of Silicon Valley and ends in the surf of Santa Cruz. In a high-tech bar, where robots wait on the customers, Michael traces the origins of modern-day search engines and social media to an institution founded by a railroad baron. At tech giant Intel, Michael glimpses the future on a test drive in an autonomous car.

At San Jose, the biggest city in the valley, Michael visits Japantown to meet members of a far eastern community who settled here peacefully during the 19th century but faced hostility during the mid-20th. He is then beaten over the head and body by youngsters a third of his age as he attempts to learn the martial art of kendo. A ride aboard the Roaring Camp and Big Trees Railroad takes Michael through groves of mammoth trees - the magnificent California Redwoods. Emerging from the forest on a second vintage railroad, Michael hits the beach and like a true beach boy, he takes to the waves - on a surfboard.