From THE HANDBOOK: THE UNOFFICIAL AND UNAUTHORISED GUIDE TO THE PRODUCTION OF DOCTOR WHO by David J. Howe, Stephen James Walker & Mark Stammers. Telos Publishing.

The authors are writing about the 1985-86 TRIAL OF A TIMELORD season:
Page 678-679

The original writers chosen to provide scripts for the season were Robert Holmes, Philip Martin, award winning playwright David Halliwell and the late novelist Jack Trevor Story. The idea was that Holmes and Martin would contribute the first two segments of evidence, each in four episodes; that Halliwell and Story would then write two episodes apiece of the third four-part segment, liaising closely to ensure that their ideas dovetailed and could be realised using the same sets; and that Holmes would then provide the final two episodes to form the concluding segment.

On Tuesday 9th July 1985, all four writers travelled to the BBC's Threshold House offices for an initial discussion with John Nathan-Turner and Eric Saward, who explained the format to them and briefed them on their respective contributions.

Despite having made great play in the press of the need for Doctor Who to be revamped, Michael Grade had apparently taken no active interest in the formulation of the Trial idea. The only advice he had given John Nathan-Turner, in a meeting reportedly lasting somewhat short of ten minutes, was that the new season should contain less violence and more humour than the previous one. The production team therefore instructed the four writers along these lines, stressing the need to avoid graphic violence and to make the stories fun and entertaining, albeit with humour arising organically out of the drama rather than grafted on artificially.

While work proceeded relatively smoothly on the segments commissioned from Robert Holmes and Philip Martin, which were given the final working titles The Mysterious Planet and Mindwarp respectively, the same could not be said of the two-part contributions by Jack Trevor Story and David Halliwell.

Little headway was made on Jack Trevor Story's segment. 'He came up with an idea for his section of the trial,' recalls Eric Saward. 'He said, "I've got an idea of a man sitting in an empty gasometer playing a saxophone." I told him, "That sounds wonderful, but I don't think we can use it in Doctor Who!"'

That's the last mention of JTS in the book. My colleague at the BBC finished the tale thus: "After that, Story was shown the door and had no further involvement."