Originally written as a play and performed at the Mermaid Theatre, Easter 1962.

It is the early 20th century. Man is seeking signs of life elsewhere in the universe, but all exploratory ships have been lost without a trace - except for DSP15. Thirty years after leaving earth, and given up for lost, DSP15 suddenly appears on radar screens at the space station at Mildenhall, England. Her crew had been frozen to prevent ageing, and as the ship settles to a landing, Dr Richard Warboys eagerly awaits with other scientists for word of what DSP15 has found. But there is no crew, only a message scratched into a metal surface, signed by the captain: "If this ship returns to Earth, then mankind is in deadly peril - God help you - " And so Earth becomes accidentally involved in a cosmic battle against a virtually omnipotent alien power, in a story suspenseful and exciting from cover to cover.