I don’t know what I expected these final installments of the first season of the show to look like. One of the great pleasures of the show is that you never really know what you’re going to get from week to week. With no overarching narrative for Roddenberry and the writers to work through, they’ve been free to tell whatever stories they can in whatever order they choose. We’ve seen a number of characters and storylines introduced that feel like perfect setup for future episodes (Mudd, Khan, the Klingons) and some of that can be felt in these episodes. While they’re not perfect episodes – altogether, they’re rather disappointing to end on – they at least set up their concepts in a way that’s consistent with the show and contain some dynamite plot elements.

Who has been the MVP of this first season of Star Trek? Captain Kirk is the traditional hero, the brash, handsome, fearless leader that sci-fi properties have relied upon since their inception. We’ve seen him take charge and solve a situation numerous times throughout the season, including a few times in this installment. But Spock is clearly the character that Roddenberry and the show’s writers are most fascinated by; it’s no accident that Nimoy is the one holdover from the show’s dropped pilot episode. With Spock, you have a wholly original creation, a blank slate and a black sheep amongst the Enterprise’s humans.

Sandwiched between two fairly solid Star Trek episodes is perhaps one of the most important entries of the entire original series to date. Even a neophyte Trekkie like myself had known of the legendary Khan in Star Trek lore, so my ears certainly perked up when Ricardo Mantalban stated his name. Of course, I had no idea of the context between his rivalry with Kirk or how it started, so to see that and have additional information for what’s to come was about as thrilling as anything I’ve seen this season.

When dealing with almost any sci-fi show, you’re bound to run into an episode or plot arc that deals with time travel. I figured it would be just a matter of time before Star Trek dipped its toes into the sub-genre, but wasn’t sure how long I would have to wait. Given the recent stretch of expansive episodes we’ve seen, Tomorrow is Yesterday fits right in, and it’s a worthy addition to the season. In fact, both episodes in this installment see Star Trek fit familiar genre tropes into its ecosystem, both yielding fantastic results.

One of the enduring themes throughout Star Trek, and a good deal of sci-fi, is in how we, as humans, are an inferior species, both technologically and mentally. It’s not only a way to build out the universe within the show, but a smart but subtle way to criticize the world of its time, whether it be for national politics or a war or a culture clash – and the 60s certainly had no shortage of all three of these. It plays into both episodes this week, creating tension in different ways that we’ve seen versions of already this season, but the execution is handled in mostly fun ways.

Shore Leave is one of the more interesting entries in Star Trek so far, but less because of what happens on the screen and more for what conspired behind the scenes. Before creating Star Trek, Gene Roddenberry created The Lieutenant for NBC and barely had a break between the two series. At the insistence of his wife and doctor, Roddenberry took a well-deserved vacation to relieve some stress. Though the script comes from Theodore Sturgeon – a prolific and respected sci-fi writer and the inspiration for Kurt Vonnegut’s Kilgore Trout character – you can see Roddenberry’s fingerprints all over the themes of Shore Leave.