Each show opened with a few minutes prologue scenes of that week's episode, and then this dialog was heard over the opening titles:
“The Invaders. Alien beings from a dying planet. Their destination: the earth. Their purpose: to make it THEIR world.
“David Vincent has seen them. For him, it began one lost night on a lonely country road, looking for a shortcut. It began with a closed, deserted diner, and a man too long without sleep to continue his journey. It began with the landing of a craft from another galaxy.
“Now, David Vincent knows that the Invaders are here, that they have taken human form. Somehow he must convince a disbelieving world that the nightmare has already begun . . . .”The show had plenty of suspense, and many very good story lines which I was eager to see every week. I haven't seen it since it went off the air in 1968, but recently acquired a set of dvds of the entire run. Upon watching the show again, I am very pleased with how well it's held up over all these years.
One of the features of the show was the special effects. Besides the occasional flying saucers, one effect was used at least once each episode, sometimes several times. Whenever an alien was killed, he or she would begin to glow bright red, flare up, and disappear, leaving no trace. Here is a photo showing a dying alien:
I was curious about how this effect was achieved, so I wrote a letter to the production company, Quinn Martin Productions. I received this reply from Howard Alston, the production manager.
I've recently read that the first season of "The Invaders" will be officially released on dvd in May, and I'm looking forward to it.
For an excellent history of the show, with photos, and a complete episode guide, go here.
Side note: David Vincent is still pursuing the alien invaders, wherever they may be. He's been seen most recently traveling through Asia, dispatching aliens one at a time.