This is a classic set up episode. Nothing significant actually happens, but all the pieces are moved into place for something very big to happen. Next episode, those pieces fall into place.
Sterling Cooper is for sale; but they don't know that. The British overlords have a plan to sell the company now that, thanks to Lane, they are a lean, mean advertising machine. The company is planning on throwing itself 40th anniversary party not knowing that it's really and horse and pony show for prospective new buyers. Bert Cooper wants no part of the celebration as it only reminds him how old he is, how many of his compatriots are dead and buried, and how the company he co-founded is no longer his. Lane goes to Bert and plays on his vanity to get him to make a grand appearance.
A late night phone call leads to much confusion for the Drapers, each believing it arose from their respective extra-marital relationships. What's the old saying, a guilty mind needs no accuser? Don is navigating the waters with Suzanne Farrell and it's becoming more complicated now that he's met her younger brother Danny, a troubled man whose epilepsy keeps him from holding a job. Betty works her way back into Henry's life, still unsure what she wants from him, and it angers Henry who doesn't want to be toyed with. But none of this matters, not compared to what Betty is about to discover.
Something is clacking in the clothes dryer and its Chekhov's keys. They are the keys to that drawer that Don keeps locked, that drawer that Betty occasional tries to open, that drawer that holds all of the evidence of Don's secret past. Thanks to a bit of absent-mindedness on Don's part, he left the key where she could find it and so Betty opens up the drawer and is overwhelmed with photos and documents and evidence that there is so much about Don that she doesn't know including a previous marriage. The question that opened the show two and a half years earlier, who is Donald Draper, is a question she is now asking herself.
We know who Don Draper is. He is a man who didn't like who he was so he shed his old identity and adopted a new one, reinventing himself. When Don comes face to face with a young man running away from who he is (Suzanne's brother Danny), he tries to tell him that he can start fresh. He can be whoever he wants to be, just like Don. As Don drives him through the night to a new job, one Danny feels is both beneath him and also one he won't be able to hold, Danny tells Don that starting new and reinventing himself is not an option. The truth as he sees it - that there's something wrong with him - will come out sooner or later.
Don wants to do right by Danny. He promised himself he'd do this right next time, he tells Danny. He's thinking back to how his half-brother Adam came to him and asked him for help, for a personal connection, and how he pushed him away. He sees another sad, directionless young man and he worries that he'll meet the same fate. Don gives his card to Danny and asks him to call if he needs help and remember that his sister loves him and doesn't want anything bad to happen to him. Yet Don ultimately only aids Danny in running away from his problems which, after all, is what Don is good at.
Betty waits up half the night to confront Don about what she found, but he never comes home. He's "out working late" the poor guy. The next morning he calls Betty and since this is not a conversation she wants to have over the phone (and without the benefit of the many visual aids she discovered) she reluctantly pretends that everything is just fine and agrees to get ready for the party. Don comes home to his beautiful wife and the perfect couple head out.
At the 40th Anniversary Gala, Roger Sterling introduces Don - the loyal husband, father and friend, decorated veteran and future of Sterling Cooper. Betty can answer that boy's question about perception; the Don she sees is not the same as the one everyone else at the party is seeing. But what is reality - what's in the shoebox or what a roomful of people believe to be true?
While the color blue was mentioned as a thought piece on what is reality versus one's own perception, there are a few moments when the color comes to the forefront in the episode. Don brings a slice of date nut bread made by his paramour to work, wrapped in a blue napkin. Lane's wife is decked out in a blue suit. Carla's wearing blue.
The secondary story line involves two different ad campaigns that both Paul and Peggy are working on. The first, for Aqua Net, starts with Paul presenting his pitch to Don but as Don starts critiquing, Peggy comes up on the spot with some great fixes that make for a better spot. He goes and complains to her for undermining him and tells her she's already Don's favorite. If only Paul could hear how Don speaks to Peggy, he'd know you don't want to be the favorite if that's how you're treated. The second is for Western Union and this time Paul - who thought of a brilliant idea but failed to write it down - sees his own mistake, and a ancient Chinese proverb he quoted, give Peggy the inspiration for another great idea. His stock is falling while hers is rising - too bad she is still not treated well by Don.
The only person with a sorrier marriage than the Drapers are the Pryces. Mrs. Pryce comes by for a visit and he asks her: "Am I to entertain your ballad of dissatisfaction or has something actually happened?" Ouch. But she does complain, about New York, about Lane, about him complaining about traffic, about taxis, and, ultimately, about her husband not being what she wants him to be. He has brought Sterling Cooper into shipshape and has impressed his bosses, but (in concert with the theme) her perception of Lane is totally different than theirs.
We learn for the first time how Don came to work at Sterling Cooper when Roger reminds Bert that he discovered him at a fur company, and that he was going to school at night. This sheds some light on their relationship and why Roger feels Don owes him more and may be resentful of all the honors and praise that Don has received. It has been made clear to Roger that Don, and not him, is the company's most valuable asset. That has to sting.
And then it doesn't help when Roger's mother is so senile she confuses his new wife Jane with his daughter Margaret. Her question, "Does Mona know?" is almost as funny as Jane's quick response. "She knows."
How is Lois still working there? And how not surprising is it that Paul is stuck with her?
Don: But the truth is people may see things differently, but they don't really want to.
Lane: So we finally have an answer to the question: "What makes Don Draper smile?" $5,000 seems to be the number.
Don: I wish you the best.
Danny: You don't even know me.
Bert: I wouldn't have told Roger if I planned on it remaining a secret.
Hooker: Very rousing sir.
Lane: Churchill rousing or Hitler rousing?
Danny: Julius Caesar had epilepsy. He ran Rome.
Don: Things didn't work out so well for him.
Spoilery Observations (Don't read unless you're caught up):
In Episode 4.6 Waldorf Stories we learn the real story behind Roger "discovering" Don Draper at a fur store.