Captain Scarlet and the Mysterons1967

The Mysterons:
[Their last line, from series finale] This is the voice of the Mysterons. We know you can hear us, Earthmen. The powers of the Mysterons are infinite. We can distort space and time. We have shown you the consequences of your primitive and aggressive behavior. It has been decided by our Imperial Council that a peaceful settlement with the planet Earth might someday be possible. So we will spare you. Be warned, Earthmen: Your warlike behavior can only result in disaster for your planet. One day, the Mysterons will return. We hope you will be ready. Someday...