Magnum P.I. was always spy-adjacent. Magnum was an intelligence officer (…or a Navy SEAL?…or both?), and multiple episodes had a espionage angle to them, usually related to Magnum’s somewhat-murky service during the Vietnam War. He even gets called back to Naval Intelligence a couple of times.
Here’s a 22-second video of one of the most infamous moments in the series. In Nam, Magnum and T.C. were captured and tortured by a KGB agent named Ivan. When Ivan reappears in Hawaii looking for them, it results in a pretty shocking ending for primetime in 1982.
Spoiler: Magnum just plain shoots him in cold blood. The episode ends on a freeze-frame which was omitted from some international broadcasts, as it was problematic. There are no details given about how Magnum gets away with the murder.
This was the ending of a two-parter (actually a two-hour TV movie back in 1982), and the next episode in the series just picks up like nothing happened, innocently guest-starring the zany brothers from Simon and Simon, even.
(I’m still really salty that Robin’s Nest was torn down. You can see it here on Google Maps — it’s never been re-developed. It would have made an amazing AirBnB.)