He accompanied Captain Richard Haliwell and a group of soldiers to investigate the surface after finding civilisation. He suffered from a heart attack after his daughter was taken by the inhabitants. He was buried near the ships' landing-site, as they had no means of taking the body back to Earth.
In the course of their time with the expedition, the Fifth Doctor and Vislor Turlough determined that Boyes-Dennison had created the impeller engine after the Vrall were able to send an RNA-encoded spore of some sort to Earth with the necessary instructions to create one, explaining how Boyes-Dennison could have made such a massive technological leap on his own. With his death and the near-calamity of the Vrall attack, the British space program was abandoned. (PROSE: Imperial Moon)