In 1977, Read was brought into "Doctor Who" by Graeme MacDonald, head of series and serials, to serve as script editor under the new producer, Graham Williams, replacing Robert Holmes in the middle of the 15th season. In the 16th season Read oversaw the "Key to Time" story arc (taking over part of the producer's duties when Williams fell ill), and shaped the character of the first Romana played by Mary Tamm. On "Doctor Who" he worked again with David Fisher, who wrote two of the "Key to Time" stories, and then wrote (or co-wrote) three more stories in the next year.