Mind your step!, sometimes called The Blackpool Exhibition video, was a small video added onto screens inside the Doctor Who Blackpool Exhibition.
It was added to the end of The Ark in Space part four as an easter egg when the story was released on DVD.
The Doctor reminds visitors to the Doctor Who Blackpool Exhibition as they leave to tell everybody about it, and also to mind the steps.
The Doctor enters and says to the departing visitors at the Doctor Who Blackpool Exhibition: "Ssh! Whatever you do, tell everybody about it. And mind the steps!" He waves, exits and then an off-screen thump and a cry of "Oooh!" is heard. It would appear that the Doctor has tripped on the steps.
- The Doctor tells people to "mind the steps", hence the title of Mind your step!.
- The Doctor mentions Superman.