Jess Trevor is one of those Gunsmoke outlaw characters that is clearly not only committed to a criminal lifestyle for financial gain, he actually enjoys what he does. The man is at least a sociopath, and possibly a psychopath. He has surrounded himself with a large gang willing to take orders.
Trevor is not content with small town bank robberies. He has formulated a plan to take control of an entire territory, and that plan includes eliminating Matt Dillon. He reasons if Dillon can be killed, it would take some time to find and install a replacement, and he could use that time to launch an unprecedented crime spree.
A woman named Leona has been involved in a relationship with Trevor, but she has reached a point where she can no longer stand his treachery. She convinces one of the gang members to split from the group and take her along.
When Marshal Dillon and Festus Haggen catch up with the pair fleeing from law enforcement as well as the Trevor gang, Leona's companion is killed in a shootout, and Leona is shot as well. When Matt sees her, he realizes it was likely one of his bullets that caused her injury. The Marshal recognizes her as a serious old flame from his days before he landed in Dodge City. Dillon takes Leona to Dodge so Doc Adams can work his magic on her wound.
(Side note: One odd aspect to the chronology in this story is that Doc Adams knows Leona and knows about her relationship with Matt. However, if their relationship took place before Matt arrived in Dodge, how does Doc know her? Of course, Matt could have told Doc about the relationship, but Doc seems to personally know Leona as though they had met previously.)
As menacing and as despicable as Trevor is, he is not exactly the evil mastermind he seems to think. The Marshal is able to capture him fairly easily, and he jails the gang leader in Dodge City while he awaits a train to transport Trevor back to prison.
Naturally, Trevor's gang is going to attempt to free their leader, and they choose to do so when the train arrives and the Marshal and his deputies take Trevor to the train.
While all of this is going on, Kitty Russell learns about Leona's past with Matt Dillon, which leads to a few scenes where the two women sort of verbally spar. They talk a lot without explicitly saying what they seem to be thinking.
Leslie Nielsen portrays Jess Trevor. This is Nielsen's only Gunsmoke guest starring role. The familiar actor was known for playing comedy roles later in his career, but he often played dramatic roles and even villains earlier, as he does in this story. His typically smooth, casual, aloof style is surprisingly effective in this part. There is one scene in particular with Jonathan Lippe (who later abandoned the Lippe stage name and used his birth surname Goldsmith) as a bounty hunter named Lucas Brant that is quite effective in demonstrating the depth of the Trevor character's depravity. (This is arguably the best scene in the episode.)
The rest of Trevor's gang is comprised of several actors that are no stranger to Gunsmoke fans. Edmund Hashim, Charles Maxwell, Robert Knapp, Kip Whitman and Sid Haig all make appearances, and they are all great in their smaller roles.
Beverly Garland plays the part of Leona. Garland is no stranger to any fans of classic television. She had recurring roles in several different shows over the years, including My Three Sons, 7th Heaven, and Mary Hartman, Mary Hartman. This is one of four different Gunsmoke appearances for Garland.
Garland's character is supposed to be a woman that has seen her share of use and abuse, but -- in all honesty -- Amanda Blake with her heavy makeup (especially noticeable in this episode contrasted with Garland) fits that description better at this point in the two careers. Garland was a fine actress, but I question her casting opposite Blake in this particular role.
This story has some intriguing elements, but it never really delivers the goods. The performances are good enough, but the presentation is poor. The whole scene near the end where Trevor is being moved from the jail to the train is especially ridiculous. Matt knows Trevor's gang is going to try to free him. There are all sorts of strangers that have suddenly appeared in town. Yet the Marshal chooses to March Trevor down the middle of the street where they can be easily surrounded.