This is a neat episode about a group of engineers who are completing a project in teleportation. The are about to test it as the episode begins. Their test subjects are a group of domesticated animals who hopefully will arrive at their destinations after the thing is triggered. When the test is made, something goes terribly wrong. There is an explosion at the epicenter, and a kind of bubble flattens out, sending a wave toward the control center, annihilating everything in its path. Just as it hits the center, the head engineer pulls a power cable from its socket and suddenly finds himself back a day or so ahead of the test. This is the deja vu of the title. He repeats this event several times, and it always ends the same way. The difference is that he observes and begins to realize that there is something unsettling and suspicious going on. For some reason this test has drawn the ire of some animal rights activists and, more importantly, the military, including an old friend, played by Ronny Cox. The head engineer, who actually stole a good deal of the knowledge from a pretty young associate (with whom he has a past), must figure out what went wrong. He must then live again (Outer Limits version of Ground Hog day) to thwart the bad guys. The whole thing is quite stunning in its thoughtfulness and presentation. One of the better episodes, surely.