What it’s mainly about

Can a fluke of time travel make it possible for Kirk to change his entire way of life, in the arms of a great love (perhaps his greatest)? What if it can be proven that this same great love, played beautifully in all senses of the word by Joan Collins, will one day be responsible (however inadvertently) for the triumph of an evil cause? Given the two-way pull on his heart and his loyalty, what will Kirk choose to do in the end?

Why it’s awesome

In this episode we get to see Dr. McCoy behaving like a lunatic, for reasons that make sense in the context, and we get to see that Spock is so brilliant, he can even forge an essential device from 1930s basic technology. Kirk as the love interest is delicious as ever. And, as mentioned, the leading lady does not leave us wanting more: say what you like about the shoestring Star Trek budgets, but they certainly knew how to feature real stars: Jill Ireland, Ricardo Montalban, and William Windom among them.