In 1939, Harrer joined a four-man expedition, led by Peter Aufschnaiter, to the Diamir Face of the Nanga Parbat with the aim of finding an easier route to the peak. Having concluded that the face was viable, the four mountaineers were in Karachi, British India at the end of August, waiting for a freighter to take them home. The ship being long overdue, Harrer, Ludwig, and Hans Lobenhoffer tried to reach Persia, but several hundred kilometers northwest of Karachi they were put under the protection of British soldiers and escorted back to Karachi, where Aufschnaiter had stayed. Two days later, war was declared, and on 3 September 1939 all were put behind barbed wire to be transferred to a detention camp at Ahmednagar near Bombay. They considered escaping to Portuguese Goa, but when further transferred to Dehradun to be detained there for years with 1,000 other enemy aliens, they found Tibet more promising, the final goal being the Japanese front in Burma or China.