Necoclí is a tiny town on Colombia’s Caribbean coast. Beach bars blast party music and sell brightly-coloured cocktails. But Necoclí is not just a tourist destination. It is also a stopping point for migrants heading to the United States. The fastest-growing group among them are Chinese. They are on a journey they call zouxian, or walking the line. Disillusioned with the Chinese dream, they have decided to chase the American version. But first they face a journey that is fraught with peril.   Necoclí is the place migrants stock up on supplies and cash, before putting their trust in smugglers who will guide them across the Darién Gap, a treacherous stretch of jungle separating Colombia and Panama. In the first episode of this four-part series, Alice Su, The Economist’s senior China correspondent, travels to Necoclí to meet Chinese migrants on their zouxian journey, and asks what drove them to leave China and take such risks. Transcripts of our podcasts are available via economist.com/podcasts. Listen to what matters most, from global politics and business to science and technology—subscribe to Economist Podcasts+.  For more information about how to access Economist Podcasts+, please visit our FAQs page or watch our video explaining how to link your account.