This is about reclaiming one's life. The Western was the dominant dramatic form on television at the time this came out, so people had a regular diet of them. In this one, a town drunk is given a chance to regain his dignity by doing something positive. He is given a bottle that will allow him to be a great gunfighter for a short time. Unfortunately, Mr. Fate has other plans and he find himself neutralized. All is not lost, however, because he and his adversary are left to live normal lives because their gunfighting days are over. This is a cold war tale and a morality play. Serling had to take it to the next level, by injecting irony. The story plays pretty well and is enjoyable and, if we have not seen it before, it plays pretty well. If you are looking for a parallel to this, see "The Chaser."