When they were at Lagung, just east of Namcha Barwa, they were arrested by the Nyerpa of Pome who took them to Showa on the Po Tsangpo river. After they had been imprisoned for several days they were released. By following this river downstream to the west and then north they reached the Rong Chu valley where Bailey discovered a tall blue poppy - now known as Meconopsis baileyi - at a forest edge. They headed south to reach the Dihang river again, this time upstream of the Gorge and just south of Gyala Peri. Hence they penetrated the massive sweep of the Tsangpo Gorge, north east of Namcha Barwa. They were able to go downstream as far as Pemakoi-chen where they found the immense Tsangpo Gorge impassible. They were only about upstream of Lagung but they had to turn to the north to follow the Tsangpo upstream to Tsetang where they left the river and headed south through eastern Bhutan to Trashigang, eventually to arrive at Rangiya back in India. The expedition covered on foot and lasted from 16 May to 14 November 1913.