Fee Wong was a timber merchant. Together with his brother Ah Wong, they ran a timber mill at Telapur along the Limpur River in the northern part of the Malayan peninsula. Fee Wong normally managed the business affairs of the company from Singapore but happened to be at Telapur when the Japanese invaded Malaya. He managed to escape but his brother, who had a fever at that time, had to be left behind. Fee Wong got aboard a prahu and hoped to travel from island to island until he made contact with British forces but was captured by the Japanese while crossing the Torres Straits and brought to Cotabato. He was injured during his captivity and was among the first batch of prisoners Biggles brought back to Lucky Strike in his Cayman amphibian. From Lucky Strike, Fee Wong was sent on to Darwin in the Liberator.
A few days later, Fee Wong returned to Lucky Strike accompanied by Wing Commander Crane on board a Saro Cloud. Crane told Biggles that Fee Wong had supplied intelligence about a valuable Japanese convoy of rubber and tin which would be transported by river barges on the river Limpur from the western side to the eastern side of the Malayan peninsula for their onward journey to Japan. At some point this convoy would pass Telapur. Fee Wong's brother was still at Telapur and he and his workman could help to sabotage the convoy.
Biggles was not keen about the mission because the chances of success appeared slim. Moreover, the location was at the extreme limit of the Cayman's radius of action. Nonetheless, he felt honour-bound to try since Fee Wong was willing to go with him. Together with Ginger and Algy, they set off for Telapur, arriving a few miles upstream. By then, however, a headwind had eroded the Cayman's fuel reserves and it did not look like there would be enough fuel to return to Lucky Strike.
Fee Wong disembarked and proceeded to Telapur to make contact with his brother. Among other things, he offered to check if there was petrol at Telapur. Fee Wong returned with Ah Wong bearing bad news. The monsoon had started early, the convoy was at Telapur under guard and the petrol had been seized by the Japanese. There was a pontoon bridge downriver with a Japanese troop column scheduled to cross within the next 24 hours. The Cayman couldn't stay as the flooding river would smash the aircraft. Nor could it take off because of the currents.
Stuck without options, Biggles suddenly heard some of Ah Wong's elephants and had the brainwave to have them push timber logs into the river. The currents would drive them as battering rams against the convoy barges and the pontoon bridge. The plan got into trouble when the timber in the river were obstructed by a fallen tree and started piling up into a massive logjam. However, quick work by Kayan, Ah Wong's foreman, soon freed the logs, albeit at the cost of his life. A massive flood of water and logs was released which tore the barges from their moorings and brought down the bridge, just when a group of Japanese vehicles and troops was crossing.
The following morning, Biggles and his team managed to steal petrol from an abandoned barge and later from a captured Kawanishi seaplane and return to Lucky Strike. Fee Wong and Ah Wong returned with Biggles and, at the end of the book, both were taken to Darwin.