A master of disguise (TV style--that stuff would never fool anyone in real lifr) is systematically framing Remington Steele for a crime he may or may not have committed. It's difficult to say.
This episode is extremely dated because of attitudes that have changed over (as of this writing) 40 years.
In the 1960s and 1970s such computers as there were, were the size of refrigerators. They were reel to reel. They were also the enemy, as in the original "Westworld" movie. They were just beginning to control our lives and danger loomed.
Remington Steele's attitude toward the computer in his office was fairly typical of his time; his shrugging off a computer class was not mere indolence but hobnobbing with the enemy. The name Quisling springs to lips several times in this episode and that's what most people would have considered those who invited this horror (computers) into their personal lives. It was a matter of trust. Lots of people didn't trust computers.
Mildred, on the other hand, embraces the new technology, as others did, though her computer might have come off the Ark. It had a tiny fraction of the memory of what I'm currently holding in my hand.
It's difficult to comprehend Remington's attitude without understanding this dichotomy. We all knew a revolution was looming; but some people, like Mildred, believed it was beneficial while others saw the shadow of Orwell in every keystroke. It was not a political, liberal/conservative division. I was a liberal writer and it took a lot of arm-twisting to get me to finally surrender my typewriter in 1988.
That apart, this episode is thick with suspense. And, finally, a plot twist that turns the case on its head. Nice writing. If you see a good TV episode, thank a writer.