Firstly, a great episode all around. It was great to see the whole gang together again and the homeages (and blatant tie-ins) were quite funny. The whole "Bob's Burgers" thing was SOOO obvious that it passed "bad," skipped over "cheesey," and landed in comedic gold. Everything from the beginnin to the end was a riot.
We got to see a different version of Sterling... slightly more innocent yet still a drunk jerk. There were still some call-backs to old jokes (purse + buckles, Krieger + Hitler clone, stickers on ta-ta's, while keeping things fresh.
It starts out like an homage to "A History of Violence" Killers enter a diner and Archer, going by the name "Bob," is working the grill. At first a little startled, he quickly goes on a "rampage" and brutally kills all of the assailants, while responding to some of them in Russian. When it's all over, he acts surprised and doesn't know how he did what he did (OR how he understood Russian). He leaves they family to keep them safe and to relax; apparently family life and the long hours at a diner were driving him nuts. He then asks them to clean up the gore, as the health inspector is coming tomorrow (I wonder if he has a band).
We then get to see the ISIS crew, who provide the exposition as to what's going on: Archer ran off after Mallory did SOMETHING and probably has amnesia. While Lana details Archer's shenanigans, we see that Mallory continues to be part of "the stuff-breaking-est family" as she breaks a couple of glasses. Ray confirms that he's (supposedly) paralyzed for real now this time and Krieger has almost an entire scene of dialog. They decide they need to ease Archer back into his real identify or else he will remain "Bob" forever. After all, this isn't some cartoon where hitting him in the head with a frying pan will solve their problems.
So they meet at the spa Archer is staying at to fake an op: Lana will pretend to be an ISIS agent on the run from Russians and ask for Sterling's help. Sterling is immediately attracted to Lana (Duh, and or hello) and things this whole thing is cool. He gets to play with Tech-Nine's, show off his hand-to-hand skills (which Lana overpowers), and laughs at the ridiculous KGB agents sent after him: Cyrill in a fake mustache and Krieger.
Unfortunately, enter the real assassins. Due to their planning, the ISIS crew only had blanks in their guns and were horribly out-matched. Ray is purposely keeping this fact from Mallory and is avoiding helping them: as he's still quite bitter over being paralyzed from last season's finale. Sterling quickly pushes Lana out of the way of the bullets while they are all pinned down, except Mallory / Pam / Carol who are enjoying the spa and assume the gunfire they hear is just Lana and Sterling firing their blanks.
Sterling is still "Bob" but demonstrating many of Sterling's traits: such as drinking, not really paying attention, and ripping off Lana's clothing as a fuse for the Molatov Cocktails (when there was perfectly good fabric 2-feet away). He starts to show more and more of his real personality, culminating in him placing stickers over Lana's breasts since he'd destroyed her clothing... and starts to remember. Unfortunately, things aren't going as planned... he's rejecting his true memories + personality and is about to lose them forever. SOOOO, Lana hits him in the head with a frying pan.
Enter Sterling Archer: code named Duchess, known from Berlin to Bangkok as the world's most dangerous spy.
While building a lacrosse stick out of materials in their hiding place, he vocalizes his anger over Lana's plan and how it almost got them killed. Using the new lacrosse stick as a weapon, he flings the Molatov Cocktails with pinpoint accuracy and kills all of the assassins. Archer is back and saves the day in maybe 30 seconds.
The conclusion shows them healing from their wounds and reveals that the "event" that gave him amnesia was Mallory's marriage to a Cadillac dealer... the number 1 Cadillac dealer in the tri-state area. They all laugh it off until they realize that it's strange that KGB assassins found Sterling TWICE in a couple of days... when not even Sterling knew where he was. They play it off as coincidence and then Carrol starts tripping balls from the LSD gummy bears... and sees an Ostrich talking.
We then zoom out and see Bionic Barry monitoring the whole thing from the space station. He's still stuck up there, and furious that he can monitor Archer all he wants but can't seem to kill him. Barry has apparently gone even darker than before, and you find out he's forcing the engineers to build him a ship so he can return to Earth. He's killed 2 already that have failed him and threatens the third with the same.
I will add this last bit: some friends were commenting that Lana and Archer's "fight" in the hotel demonstrate that she's more dangerous. However, as the bar scene showed... Archer was still not in total control of his skill-set until he returned. I imagine it's still possible that if the two ACTUALLY fought... they'd be evenly matched.