In Biggles in the Orient, Sergeant Gray was a fitter-rigger with A Flight of 818 Squadron. A man of around 30, Gray had an exemplary record and had been with the squadron since it was formed at Kenley. Gray took special care of the machines under his charge and went over the airframes and engines in great detail. He therefore took it very hard when many of his pilots failed to return. Biggles, who was investigating the mysterious crashes, decided to speak to Gray as he was the last person to touch the Hurricane of Thomas Grafton Moorven, the most recent fatality. Biggles and Johnny Crisp went in search of Gray and found him on the hangar floor, apparently drunk.
Crisp had reprimanded Gray a few weeks ago for drunkenness. Caught again, Gray denied that he had been drinking. He had merely been sitting there "chewing things over". Not able to question him in this state, Biggles and Crisp forced some coffee down him and put him to bed.
A short while later, Crisp called Biggles to Gray's room again--Gray was dead. At first the doctor thought the death could have been the result of drinking, which, coupled with the heat, could have led to heatstroke. Either that or the heat could have caused him to run amok and commit suicide. However Biggles enquired at the Sergeant's Mess and found that Gray had only drank an iced lemonade and did not not seem unduly upset or agitated. He had also found a piece of chewing gum wrapper on the hangar floor near Gray. In Gray's room, he had found a coffee pot which was still warm, suggesting that someone had returned to Gray's room after Biggles had left him there. From these slender cluse, Biggles concluded that Gray had been murdered and was able to form some idea of who the murderer was.