In Murder by Thirst, Black Jack Barnes was an ex-convict and trouble maker from Western Australia who partnered with an elderly novice English prospector Mr Farlow in search for gold in the Western Australian desert and later murdered him.
Farlow, a retired English businessman, had gone to Western Australia to live out an ambition to prospect for gold. On arrival, he had advertised for a partner, with the idea of tying up with someone who knew the practical side of prospecting while he supplied the capital. Barnes had a bad reputation, was frequently drunk and loved to pick a fight. Nonetheless, he must have seen the advertisement and somehow persuaded Farlow that he was the right man for the job. Before any of the locals could warn Farlow, he and Barnes had departed into the desert on their expedition.
According to a note left behind by the deceased Farlow, he and Barnes had struck a rich vein of gold. Driving back to register their claim, Barnes had, either by design or accident, stuck the jeep in deep mud. They started walking but on the first night out, while Farlow had been asleep, Barnes had abandoned him, taking all the remaining water.
Barnes and Farlow was subsequently posted as missing and an air search was conducted for them but without success. Barnes somehow made his way undetected to Darwin where he boarded a plane, intending to travel to London to interest one of the large mining companies there about his find. Unfortunately for him, two music students from Western Australia John Murray and Sally Dunn spotted spotted him on their plane. Knowing Barnes' reputation and his supposed disappearance with Farlow, John and Sally became suspicious and decided to report their suspicions to Biggles.
Biggles, following up on their report, found that Barnes had come to London to tie up with the Antipodes Mining Corporation. He had returned to Western Australia with a mining engineer and surveyor in a plane belonging to the company. Following on their trail in cooperation with the Australian police, Biggles subsequently located the body of Farlow in a clump of mulga. In Farlow's pocket was a letter he had written describing what had happened. Armed with this evidence, Biggles and the Australian police arrested Barnes.