It turns out that the two criminals (Steve Deal and Norm Landon) are on the lam from a failed robbery that left their third partner dead. Ironically, the police dispatcher was giving details on the robbery when Reed and Malloy rolled up on the camper truck, but they had ignored it. In fact, they were a bit annoyed by the dispatch because it was keeping them from running the license plate or giving their location. That last part didn't stop them from telling their kidnappers the exact opposite and tricking the criminals into thinking that the LAPD was now looking for their camper.
The two criminals are joined by the sister (Susan Danhart) of their dead partner, who is led to believe that Reed and Malloy were the ones who killed her brother. Let's talk about the Norm and Steve for a second. The Norm, the leader, was fairly reasonable and obviously didn't want to cross the line and murder the two cops, knowing what the consequences would be. He's also accused of cowardice by the second man, who also claims that it caused the death of the woman's brother. Then there's Steve. Now there's a guy who's two scoops of fucking nuts. Unlike Norm, he's pretty intent on murdering the two hostages, especially Malloy, who shot him in the shoulder. As the episode progresses, Steve becomes less and less stable to the point of holding Norm at gunpoint when it looks like he's going to pop Reed.
Honestly though, my favorite part of the episode and this really showcases how unhinged Steve was becoming is when Norm sends him off to steal a new getaway vehicle (believing Malloy that the camper is on the LAPD's radar) and the man comes back with a goddamn school bus. I cannot make this up!
But then, things get real. When the group arrives at the farm of Joy's father (to escape to Mexico in his plane), Steve takes Malloy to kill him and for an episode of a TV aired in 1973, this scene is intense. He forces Malloy to his knees like he's going to kill him execution-style, but fortunately, Reed is there to save the day. You see, during the scene where they were ditching the camper, Jim was left alone with Susan and he planted the seed of doubt in her head that him and Pete killed her brother. Steve deep-sixed the lie during an outburst on the bus and Susan snuck Reed the key to his cuffs when the two criminals were leaving the bus with Pete. So anyways, Jim and Pete manage to take Steve down and escape into a nearby field, but are slowed down by Jim's leg wound. Add the lack of a gun to defend themselves and they have to act clever and they do. Malloy has Reed act as a decoy so that he can sneak up on the duo and they both take them out. The episode ends with them driving the bus back to the Susan's father's house as a police car speeds towards them. Jim and Pete share a look, like "What a fucking shift."
Martin Milner: Pete Malloy
Kent McCord: Jim Reed
Michael Richardson: Norm Landon
John Chandler: Steve Deal
Joy Bang: Susan Danhart
Writer: Stephen J. Cannell
Director: Lawrence Doheny
My take: Killing Ground was a pretty good episode that manages to convey a sense of dread and fear by not only having the two main characters of Adam-12 kidnapped, but putting two police officers as the victims and in mortal danger. This isn't an uncommon trope in cop shows, but this managed to make you worry for the lives of Pete and Jim, even though you knew that they were never in danger of being killed off. My only complaint is that Jim's leg wound didn't really play into the plot until the end. I mean, he takes a bullet and spends most of the episode with it untreated and you don't see him in pain at all.
What's interesting about this episode though is that it may have been based on a real life incident in 1963 where two plainclothes LAPD officers were kidnapped by two criminals during a traffic stop and later taken to an onion field where one of the officers was murdered while the other managed to escape. A book about the incident by Joseph Wambaugh named The Onion Field was released in 1973, the same year Killing Ground aired. The episode aired months before the book's release, but given Jack Webb's relationship with the LAPD, it's not a stretch that Webb would want to do an episode based on such an infamous incident.