We begin by getting a glimpse into Jim's home life as he waits to hear from the head of his party (and the New Prime Minister) as to what his new job might be. His wife Annie who we will see repeatedly throughout Yes Minister (and Yes Prime Minister) shows that she has a pretty good handle on being a politician's wife and can hold her own. When the call finally comes (after a series of humorous other calls), Mr. Hacker learns he will have his own department and be a part not only of the new government, but also the cabinet as the Minister for the Department of Administrative Affairs.
We meet his private secretary, Bernard Wooley and his political adviser as Mr. Hacker arrives for his first day "at the office." While the political adviser is safely distanced from the Minister and temporarily out of ear-shot, Jim gets to see his office and meet one of the other key characters in the show.
His first meeting with his permanent secretary, one Sir Humphrey Appleby, sets the tone for what will ensue. Humpy (as he is sometimes affectionately called) is a master at saying volumes without actually saying anything at all. In fact on the rare occasion when one might actually succeed in getting Sir Humphrey to say something of importance or relevance, and should he take the unprecedented step of going so far as to actually answer your question, you will probably find, at the end of the day, when having taken all sides into account, that by the time you got to the answer that was not expected, but actually given, that one had so lost track of the central point, so much so that despite having been provided with the aforementioned answer, one no longer recalled what was the question was, so as to effectively render the answer ineffective.
And if you can follow that, you will love the show.
In his first act as Minister, Jim wants to squash an order for computer monitors worth quite a lot of money that is going off-shore to the Americans. Humphrey (as usual) knows the entire back story to the whole affair, but only feeds bits and pieces to Hacker and his political adviser, one Frank Weasel, oh excuse me, Weisel. From this misinformation, Hacker plans a press release that while seeming very pro-Britain (and an example of open government) will actually serve to embarrass the new Prime Minister who is eager to make a good impression on his upcoming visit to America.
Jim is called to number 10 when word of the impending press release reaches the Prime Minister's office and just when things look their bleakest, Bernard arrives to inform the Minister that due to an oversight (that was no oversight at all) the press release was stopped before it got to the media by an existing check put in place by Sir Humphrey. All at once, Jim is stopped from doing what he wanted to do, Humphrey gets exactly what he and the civil service want (looking like a hero in the process) and the government goes on quid pro quo.
The episode ends with what will be the catch phrase for all but a couple of episodes in the series "Yes Minister."