Douglas Camfield, with whom he would often work in later years. In 1969 he was promoted to assistant floor manager. In 1975 he was promoted again and became a production assistant. One of the first productions he was assigned to in this role was the Doctor Who serial "The Seeds of Doom", again working under director Douglas Camfield. In 1980, Harper once more worked on Doctor Who when he was assigned to be production assistant to director Paul Joyce on the serial "Warriors' Gate". Joyce's approach to the production resulted in various delays, and Harper had to take on extra responsibility for helping to direct the serial in order to ensure it was finished in time. Following this, Doctor Whos executive producer and producer, Barry Letts and John Nathan-Turner, endorsed Harper's application for the BBC's in-house television director course, from which he graduated in 1982. Harper's first television directing work consisted of episodes of the medical drama series Angels. In 1983, John Nathan-Turner offered him work on Doctor Who, but as he could only employ freelance directors, Harper would need to resign from the staff of the BBC first. This Harper did, and he began working on Doctor Who in the autumn of 1983. Freelance work Harper's first Doctor Who serial, The Caves of Androzani, was the last Doctor Who story to feature Peter Davison in the title role. Produced in late 1983, it was broadcast in March 1984. It is widely regarded by fans of the programme as one of the finest instalments of the series. Davison has been especially complimentary about Harper's direction of the story, claiming in 2009, "Graeme’s philosophy was that it needed pace and it needed energy. Graeme’s input, and the fact that it was a great script, really lifted it, I think." Davison has also claimed Harper "directed far more filmically than it had ever been done before." In 1985 he worked again on the programme, directing Revelation of the Daleks, starring Colin Baker. In 1989 he was approached to direct the Sylvester McCoy-starring Doctor Who serial "Battlefield", but he was committed to episodes of the Central Television drama series Boon. In 1993 he was attached to the potential Doctor Who thirtieth anniversary special "The Dark Dimension", but this was abandoned at the pre-production stage. Harper's other work has included episodes of Juliet Bravo (1984 & 1985), Bergerac (1985 & 1987), Star Cops (1987),