(1969) A transporter experiment results in duplicating Mr. Spock. One of the Spocks is eeeeevill ... but which one? Meanwhile, the Klingons have violated the Organian peace treaty and started a war on the Federation. It's not a great episode, but it is a curious visit to (what are now) the early days of the franchise, when much of the series' Bible hadn't been written yet and it shows. And for that it's fun.