In Another Job for Biggles, the Wadi al Arwat was a wadi in the Rub al Khali or Empty Quarter of the Arabian Desert located about 150 miles in the hinterland north of Aden. The noted explored Doctor Guthram Darnley passed through the Wadi while crossing the Empty Quarter. There he found a party of about 30 Murra Arabs whom he believed to be once part of a large raiding party. The Arabs were all in a semi-comatose state as were their camels. Darnley discovered that this was to the Gurra plant which grew in the wadi. The Arabs had been using the shrub to tend their fires and had inhaled the narcotic fumes. Their camels had been using the shrub as fodder. Not in any fit state to travel, it was only a matter of time before the party of Arabs died.
Biggles was sent to the wadi to burn the Gurra plants to prevent them being used as a source of narcotic drugs. When he arrived, he found the plants already burnt. It transpired that three of the coast Arabs who had accompanied Darnley, Abu bin Hamud, Kuatim and Zahar, had decided to go back to the wadi and collect some Gurra seeds for cultivation. Once there, Abu bin Hamud betrayed the other two, collecting the seeds, burning the plants and then making off with the camels, leaving them to die. When Biggles arrived on the scene, Kuatim was already dead but Zahar was still alive and able to tell Biggles what had happened.
The Wadi al Arwat is a fictional location.