PLOT: Workers in an underground data-storage facility are mysteriously killed after excavating a tunnel for a new wing. Kolchak apprehends evidence of a reptilian creature and its motivation for the slayings. Tom Bosley of Happy Days has s small role as a host at the facility.
COMMENTARY: The story is a rip-off of Star Trek's excellent "Devil in the Dark" from eight years prior, but the writing isn't anywhere near as absorbing, although it's moderately entertaining. The monster costume isn't too bad for the mid-70s, but they should've kept the viewer from seeing the almost comical face/teeth. Less would've definitely been more in this case.
This episode is notable for being the final segment of the franchise. McGavin was becoming disillusioned with the show due to an exhausting schedule and the fact that he was rewriting scripts plus doing much of the production work without compensation. The ratings were mediocre so he asked to be released from his contract with two episodes yet to be shot. The network granted his request in light of the declining ratings. I wish Darren would've persevered and finished out the season because then we'd have two more episodes to enjoy. He was too fatigued at the time to see that this unique and seminal show would be his most well-known role, along with "A Christmas Story" (1983).
Another highlight is the beaming & lovely Kathie Browne as Lt. Irene Lamont. Kathie was McGavin's wife for 34 years until her death in 2003. You might recall her as hottie Deela in Star Trek's "Wink of an Eye" from seven years earlier. Unsurprisingly, her & Darren have great chemistry.