The first ever commercially produced Doctor Who audio was the 1976 Argo Records production, Doctor Who and the Pescatons, starring Tom Baker and Elisabeth Sladen as the Doctor and Sarah Jane Smith. To be honest, it is not fantastic. The plot is ripped off by writer Victor Pemberton from his Second Doctor series Fury from the DeepExploration Earth, also from 1976, an educational radio programme which just has the Doctor and Sarah travelling through time and observing the gradual geological development of the planet Earth, with a chrome alien attempting to disrupt things, who is despatched rather casually at the end.