The Enemy are life-spores which infect history and transfigure it so that they were always there. Spores infect the human crew of the spaceship Narcissus and spread backwards along their lineage to the planet Earth. Thus the Enemy begins to attempt to bud in the mid-20th century, at first failing to get enough psychic energy to assert their new history. The Enemy comes close to success by infecting President John F. Kennedy in 1967 during his second term in office, but by chance the President dies of a heart attack just before he can be transformed.
An agent of the Great Houses comes to the morgue to examine Kennedy's body. Seeing that the Enemy will still be able to fester in Kennedy's timeline, the agent decides that Kennedy must be terminated at a point before he was infected with Enemy spores.
- The story was preceded by Pre-narrative Briefing A.
- The life-spores infect the British Rocket Group. (TV: Remembrance of the Daleks, et al)
- Time Lords were previously shown to be behind the Kennedy assassination in PROSE: Untitled and PROSE: Who Killed Kennedy.