Cameron Dennis has succeeded in scraping up an additional witness for Ava Hessington's murder trial, but that's pretty much just a framing device for a series of flashbacks to ten years ago. In those days, Harvey was flying high at the D.A.'s office, under Cameron Dennis while trying to get a leg over Donna. Harvard-bound Mike and his then-buddy Trevor joined a back room poker game with some other douchebag college students who cheated them out of Trevor's first dope-selling proceeds. And Jessica was a lowly partner at Gordon Schmidt Van Dyke.
Except most of that is about to change, because 2003 Trevor talks 2003 Mike into selling his first math test, because he needs the cash to pay off a drug dealer. Which happens, but then Trevor gets arrested for selling the test. 2003 Cameron ignores arguments from 2003 Harvey (and, indirectly, 2003 Donna) to bury some evidence, which Donna discovers is a pattern on Cameron's part. Also, 2003 Jessica is planning a coup against the senior partners with 2003 Daniel Hardman.
Young Harvey goes to his still-living dad for advice, as Young Mike goes to his still-living Grammy, and they respectively think Cameron and Trevor need to be told to go screw themselves. Harvey does, but Mike confesses to stealing the test, and not only gets expelled but loses his shot at Harvard. Harvey decides to go to work for Jessica, and brings Donna with him, but not before they take advantage of the brief window in which they aren't working together. So their professional relationship resumes and their romantic one ends almost before it starts. Almost.
In the present, Cameron's witness turns out to be the foreign colonel that Ava Hessington confessed to bribing. Cameron offers Harvey a deal in the form of a prison sentence in the low double digits, but Harvey's not hearing it. Stephen Huntley's advice that he take it doesn't help either, given that Harvey finally admits that Stephen's relationship with Donna bothers him. Meanwhile, Rachel visits Stanford, and Mike belatedly gets supportive and promises to tell her about his Harvard acceptance back in the day. Harvey confesses to Jessica about his deal with Darby, about which he has changed his mind, but Jessica's still pretty pissed. Too bad she already put Harvey's name on the door.
Finally, Mike busts Cameron for bluffing about the colonel being on his way to testify, but there's bad news: Cameron's no longer bluffing about that, thanks to Stephen Huntley. Okay, how did that foul-up ever end up on Darby's right hand in the first place?
Donna and Louis are riding up together in the elevator, and when she senses his good mood, he "reluctantly" tells her about some recent bits of good fortune, including a turning point in his relationship with Nigel's cat Mikado, five new hairs on the top of his head, and his sister's broken foot. "Serves her right. Dad's favorite." But his mood goes quickly south when they step off the elevator and are both stunned to see the new sign on the wall reading "Pearson Darby Specter." Without even bothering to turn around, Louis reverses right back into the elevator, saying, "I need a day."
Donna heads on into Harvey's office, where she has two questions: when did he find out about this (last night) and why didn't he tell her? He says he shouldn't have had to, and accuses her of being distracted lately. Donna wants him to admit that her relationship with Stephen bothers him, which he refuses to do because he continues to insist that it doesn't. "I've never had to tell you a thing," he adds. "You've always just known."
And with that, we're suddenly ten years in the past, at the New York District Attorney's office. Which we already know is where Harvey and Donna were working at the time. Now, in this sepia-toned flashback from beyond the deep mists of pre-history, Donna demonstrates that back then she can still tell how much coffee Harvey has had by the quality of his signature, even as a giant 2003 wig threatens to eat her head. Harvey and his Richie Cunningham hairdo challenge Donna's observational talents. So she proves them to him by going all Sherlock Holmes on him, deducing from his appearance all manner of conclusions from a big poker win the previous night to his current single status.
Cameron Dennis -- who had graying hair and a mustache then, too, just four years after Gary Cole was in Office Space -- comes up to talk about a couple of murder-defendant brothers who are in the house. Harvey suggest his idea relating to the "Night Owl murders," which Cameron both recognizes as an L.A. Confidential reference and shoots down.
Harvey unwisely comes right back at him by mocking Cameron's own The Untouchables-derived plan -- unwise because it causes Cameron to do a bad Sean Connery impression. After Cameron leaves, Harvey does his own bad Connery for Donna, and accuses her of being into him, which he thinks is the only way she should be able to tell as much about him as she can. Donna says she's just Donna, meaning, "I could do the same thing with Bertha [a very large woman working nearby] that I did with you." Harvey figures that means Donna is into Bertha too, and suggests a threesome. Which Donna shots down, saying Harvey would never want to share her. As she leaves, Bertha just shakes her head at Harvey, who grins at her like he wouldn't turn down a threesome with Bertha and anyone.