In Biggles Goes Home, Captain John Toxan was a retired Indian Army officer who prospected for rubies in the jungles of Gharwal. He met and took care of Mr Poo Tah Ling when he escaped fro Tibet. Toxan later sent a message to London requesting help to transport Poo to safety.
At the time of the events in the book, Toxan, accompanied by two Gurkha assistants, had been digging for rubies for 6 years in the Nullah Tangla, a deep ravine near the Timbi Tso lake in the jungles of Gharwal. When Mr Poo Tah Ling descended the Himalayan foothills during his escape from Tibet, he and his Tibetan servant came across Toxan's encampent in the nullah. Toxan realized that Poo was in poor health and took him under his wing, giving him food and shelter. After a time, Toxan thought he wanted to retire from prospecting but felt he couldn't leave Mr Poo behind. As he and his Gurkhas couldn't carry Mr Poo with them, Toxan sent a message to the British government requesting that someone come and collect Mr Poo.
Biggles and his crew were detailed for the mission and subsequently arrived at the Timbi Tso lake. Unfortunately for Toxan, a party of Chinese soldiers were also in the area looking for Mr Poo and they found Toxan's encampment first. The Chinese took Toxan by surprise. Toxan and his Gurkhas put up a brief resistance but they soon had to retreat into the jungle. One of the Gurkhas had been killed and Toxan himself had been wounded in the shoulder. Poo and his servant managed to escape and hide in the scrub but were captured by the Chinese later.
When Ginger and Algy flew over the nullah and spotted the aftermath of the battle, Ginger decided to parachute in to investigate. He found Toxan hiding in the jungle and treated his wounds. Biggles and Bertie arrived next, and with the help of Hamid Khan, one of the Gurkhas working for Toxan, Poo was rescued. The party now set off for the lake carrying Toxan in an improvised stretcher where they boarded the Gadfly. Toxan was flown to a hospital in Delhi for treatment. He left a tin of rubies with Biggles, telling him he would collect them when he returned to London.