It was rare that producer Quinn Martin stepped away from the crime drama genre that put him on the map. There are at least three instances. The first was the military drama, 12 O'Clock High. The last was Tales of the Unexpected, in the late 70's. In between was The Invaders, a science fiction series that bowed as a mid-season replacement in January 1967 on---where else?---ABC, but ultimately lasted just 14 months on the air.
The story goes that Martin was looking for something of a tentpole series to replace The Fugitive, which was in its final season. Created by Larry Cohen (Branded), The Invaders told the story of David Vincent (Roy Thinnes), a lone witness to the landing of an alien spacecraft. These beings came from a dying world, seeking to colonize the Earth and convert it to their liking. Oh, I'm sure you've probably read stories like that before and since, and the concept invoked memories of the 50's feature film, "Invasion of the Body Snatchers". The gimmick here was that the aliens could be identified by having an extra finger, an inability to bleed, and, if captured or killed, their bodies would dissolve into virtually nothing, leaving zero clues behind. Over the course of 14 months, Vincent built a small group of allies, but, sad to say, the conflict didn't reach its resolution at the end of the series. Nearly 30 years later, the concept was revisited in a miniseries on Fox, rather than ABC, with Thinnes reprising as Vincent and passing the torch to a new hero (Scott Bakula, Quantum Leap).
Dick Wesson was house announcer for QM at the time. The narrator is Bill Woodson, better known for similarly setting the stage a few years later for The Odd Couple, before moving to cartoon work in the late 70's. Jimmyredproductions uploaded the open to the episode, "Genesis".