In Peiping, the Republic of China, female student Lin Wanqiu rescued diplomat Lu Jingming who was being hunted by spies during a patriotic parade. Lu Jingming appeared to be a diplomat, but in fact he was a patriot who secretly provided help to the anti-Japanese organizations. Lin Wanqiu was moved by Lu Jingming's patriotism and became his "liaison" to help him deliver secret information in diplomatic documents. The two gradually fell in love with each other, but they faced the pursuit of the Japanese army and the suppression of the Kuomintang agents. In the end, Lu Jingming completed his diplomatic mission and took Lin Wanqiu to Chongqing to continue fighting for the anti-Japanese cause.
