 " Blink " was written by Steven Moffat . Part of the story for " Blink " is based on Moffat 's own Ninth Doctor short story from the Doctor Who Annual 2006 called " ' What I Did on My Christmas Holidays ' by Sally Sparrow " . The short story is presented as a homework essay from Sally , though only 12 years old , who encounters evidence of the Doctor 's presence from the past in her aunt 's house while visiting . " What I Did " includes several elements that are reused in " Blink " , including messages under the wallpaper and an ontological paradox involving a conversation between Sally and the Doctor , prerecorded on a video cassette , based on a written transcript — the essay itself ; however , instead of the Angels , " What I Did " features the Doctor and the TARDIS inadvertently separated twenty years in time by a fault in the time machine , and the Doctor is able to instruct Sally how to bring it back to him in the past . 
