The full phrase was used in several Target novelisations. It was subsequently used by the Fourth Doctor (in "City of Death") and the Fifth Doctor (in "Castrovalva" and "Mawdryn Undead"). Together with "The Five Doctors", this resulted in the phrase being used as a nostalgic reference. In the Tenth Doctor episode "The Lazarus Experiment", the Doctor, while hiding in Lazarus' machine, comments that it had taken him too long to reverse the polarity due to being out of practice. The Tenth Doctor uses the full phrase in "Music of the Spheres".