The Doctor and Andric head to Earth to fix the TARDIS's chameleon circuit. Once there they face danger involving a newly regenerated Master and a feisty young air hostess named Tegan Jovanka. How can the people of the distant and mysterious planet Logopolis help? And just who is the strange, ghostly figure watching the Doctor's every move?
This is item 35 in The Doctor Who: The Fourth Doctor, Tom Baker (1974-1981) Series.