Written by Alan Wakeman. Wakeman was one of several writers contacted by David Whitaker in mid-1963. The story was commissioned on 31 July 1963. It involved a planet ruled by sentient rocks and trees, with the ability to control humans with an inaudible sound. A four-part episodic storyline breakdown of the story featured in the third volume of the magazine "Nothing at the End of the Lane". In this breakdown the following episode titles are quoted: "Airfish", "What Eats What", "The Living Planet" and "Just in Time". Note that in the script, Susan is referred to as Suzanne, and Barbara is referred to as Miss Canning.