4th printing, with updated cover design. Novelization of the 6-episode 1967 storyline, adapting the teleplay by Mervyn Haisman and Henry Lincoln. The edition published as No. 1 in the Doctor Who Library; beginning in 1982-83, Target assigned book numbers to its novelizations. Numbers were initially assigned based on title alphabetical order, not broadcast or publication order. Illustrated by Alan Willow. 144 pages.