That's not Cooper. Well, we already knew that, but now we have confirmation from Diane Evans (Laura Dern) herself. We also learn that the doppelgänger's fingerprints are backwards, as evidenced by the fact that they fail to line up as the first letters of the proper greeting that Gordon (David Lynch) referred to earlier: "I'm very, very happy to see you again, old friend." Layers.

We also learn about a night Cooper and Diane spent together, a night that still haunts her as she chain-smokes, drinks, and grimaces. (Diane seems to have had at least some good nights since, with Don Johnson's son Jesse.) Initially it's unclear whether that night was with the original Cooper or the doppelgänger, but once they've met it becomes clear. "That," a distraught Diane tells Gordon, "is not the Dale Cooper I knew."

The not-Cooper is on the loose again by the end of the episode, having blackmailed his way out of the federal pen with some information about Gil McCluskey and a "Mr. Strawberry." Memo to self: if you're ever a federal prison warden, don't get involved in any compromising situations with former Major League Baseball all-stars.

We also learn the fate of Major Briggs: that was his headless body found in South Dakota. At least, that's what the prints indicate...but where's his head, and why is the body that of a man who would have been over two decades younger? (I appreciate that Twin Peaks is more attentive about matters of age than the current season of Fargo.) Perhaps Major Briggs has been spending time at near the speed of light, with his alien friends? I believe. Unfortunately, Don S. Davis, the actor who played Major Briggs, died in 2008.

Dougie haters will be glad to know that we don't have to watch Kyle MacLachlan stand mutely for too long this episode, although Cooper-as-Dougie has a big scene where he saves himself and/or Dougie's wife Janey-E (Naomi Watts) from Ike "the Spike" Stadtler (Christophe Zajac-Denec), the wiry assassin who works for one of the two competing crime syndicates Dougie seems to be caught up with. (It seems likely that one of them is looking for the doppelgänger Cooper.)

Remembering his training instinctively, the real Cooper snaps out of his stupor for long enough to wrestle the killer to the ground and grab the gun — seemingly taking part of the hitman's hand with it, at the behest of the Arm. The little tree-brain springs up right there in Las Vegas, hissing something like, "Freeze his hand off!" Or was it, "Tweeze his hand off?" Or, "Please, his hand off?" Something like that. Update: Subtitles say, "Squeeze his hand off." H/T commenter below!

Remember when this used to be a show about Laura Palmer? Hawk (Michael Horse) does, and he knows what he has when he finds three of the four pages ripped by Leland Palmer from Laura's secret diary. (Shout-out to Harold Smith!) The pages were stuffed into the door of a bathroom stall at the sheriff's office — the log led Hawk there, obliquely — and even though that means they would have been written prior to her death, they seem to refer to the fact that Agent Cooper would later get trapped in the Black Lodge.

"My name is Annie," wrote Laura, relaying words that she says came to her in a dream. "I've been with Dale and Laura (me??!!!). The good Dale is in the lodge and he can't leave." Hawk and Sheriff Frank Truman (Robert Forster) surmise that refers to Annie Blackburn, the Heather Graham character who went into the Black Lodge with Cooper during the season finale. She got out all right, we were told...or did she?

(On another page of her diary, high school English teachers everywhere will appreciate the detail that Laura spells "breathe" as "breath.")

So the authorities are starting to figure out what's up with at least two of the Coopers we've seen. The Vegas cops are also on the trail of Dougie's detonated car, though they assume — with some emphatic help from Janey-E — that it was stolen by the guys who died with it. In that same scene at the insurance company, we see the nervous coworker who Cooper earlier called a liar, and start to surmise that the little doodles he's been drawing are pointing to some kind of fraud on that guy's part. The truth will out, eventually.

The remaining plot thread being chased in this episode is the trail of the truck that so brutally killed a young boy in episode six. Andy (Harry Goaz) finds the truck, but not the driver. Good police work so far, except Andy lets the truck's extremely nervous owner promise to meet him later rather than hauling the guy in immediately. The owner doesn't show up for the rendezvous, and we don't know what happened to him — but we get an ominous shot of an open door at his humble domicile, and we suspect that the showy drug kingpin who employs Richard Horne doesn't appreciate having the five-O sniffing around.

We still have almost a dozen episodes left to go, so why not get to know some new characters? Towards the end of the episode, we see Ben Horne having a (by his standards) restrained flirtation with one of his employees, Beverly (Ashley Judd). After Ben marvels at the old key that's just arrived in the mail — a key that just happens to correspond to the room where Special Agent Dale Cooper was shot — Beverly goes home to her very sick, yet still possessive, husband Tom (Hugh Dillon). Yet another Twin Peaks character trapped in a suffocating relationship.

We also meet an old friend: Doc Hayward, who's Skyped in by Frank Truman. There's actor Warren Frost, who died last year at age 91, wearing a "Got trout?" cap and reminiscing about the night Agent Cooper went into the Black Lodge. Audrey Horne, Hayward reveals, ended up in a coma after the explosion at the bank — opening a new set of questions about what her status might be now.

Sheriff Truman sends his old friend off with a blessing: "Keep working the sunny side of the river, Doc."

Catch up with season three

Twin Peaks returns, with the Cactus Blossoms and a whole lot of whaaaaaaa???

Twin Peaks episode five recap: The cow jumps over the moon

Twin Peaks episode six recap: Diane! and Sharon Van Etten