Oh boy, was last night's episode of Grey's Anatomy a doozy, or what? Between staring at the returning gorgeousness of Kate Walsh and shushing my roommates (they're chatter-boxes!), I almost missed all the (not-so-sub) subtext in the episode.

The day starts off with a bang. Addison is back, Ava (Elizabeth Reaser) is pregnant, and MerDer's new clinical trial is in full swing. Except Addison mistakenly thinks nothing has changed, Karev blows Ava off, and the trial patient (tumor guy from last week) is getting worse. Uh oh.

The case Addison has returned to work on is the medically improbable patient of the day: A pregnant woman whose in-utero baby will be born with its heart on the outside of its body, and it seems as though half the doctors in Seattle Grace on working on the case.

But this is where things get good. When Callie joins Drs. Hahn and Montgomery in the hallway, the two new BFFs gush to each other about how great Addison is, and then reveal to Addison that Callie has gotten a divorce. They are finishing each other's sentences like old pros.

Erica: Does she know you're divorced? [Callie nods to Addison]
Addison: You're divorced?!
Erica: Which, as it turns out …
Callie: [smiles and nudges Erica] … is the best thing that could have happened, really.

The two stroll off into the distance — Callie's arm over Hahn's shoulders — and Addison watches them, mouth agape.

Ava found Karev again and tries to talk about her pregnancy, but he isn't having any of it. He storms out to go care for his pregnant patient with the overly happy husband. Karev does the Karev thing and starts yelling at the parents-to-be, telling them how hard everything is going to be and how unprepared they are. (Projection, much?)

But I don't mind, because it prompted my new favorite Bailey-ism: "Karev, right now you're feeling all your feelings right out in the open. Do me a favor and stuff them back in." It appears as though "the Nazi" is back. Thank goodness!

It's lunch time at Seattle Grace, and confrontations are abundant. Yang told Callie that Hahn is no longer allowed in their apartment, and after Callie told her to tell Hahn how she feels, Christina informs them that she "doesn't speak girl." Whatever that means.

Addison noticed how friendly Callie and Erica were earlier, and then witnessed the Callie-Christina exchange, so she humorously (but earnestly) asked Callie if she and Hahn were seeing each other. Callie laughs and denies and denies and laughs, but her expression alone says there is more to the story. (Note to Callie: Declaring that you "like penis" isn't exactly the most convincing way to squash those rumors. Humorous? Yes. Effective? Not so much.)

We find Christina inside sitting down with the other residents (plus George, the lowly intern), and she tries to "talk girl" by asking Alex about his feelings, but miserably fails at conversing like a normal human being. Callie interrupts to ask Christina and Meredith if they are ever mistaken for a couple (no, they are too busy "screwing boys"), and Yang finds another way to get to Hahn: She gives Callie an ultimatum. Either get Hahn to let her scrub in, or move out. When Callie suggests it to Erica, she agrees — if Callie buys their drinks at Joe's that night. Gulp.

Izzie has a pregnant patient who reveals she wants to abort the baby because she is HIV-positive, and Izzie doesn't know how to handle the situation. Meredith and Derek's clinical trial patient goes blind and they have to move the surgery up, and after trying to pimp his wife out the entire episode, the guys become nice for the first time just before surgery — which on this show is the kiss of death.

During the requisite surgery montage, we see both mother and baby survive (drama-inducing uncertainty included), but the tumor patient isn't so lucky.

After surgery, Addison stirs up more trouble by pressing Bailey as to what has been wrong with her, and Bailey verges on emotional. But being the hardass that she is, she remains only on the verge. Then Izzie finally grows some cojones (Gross. Forget I just said that.) and tells her pregnant HIV patient that she isn't discouraging the abortion because of some great political agenda, but because her baby has a 98 percent chance of being born healthy. (Wow!)

Elsewhere, in The Elevator of Awkward, Derek, Meredith, Addison, Rose and Mark all find themselves with no escape. I would have probably found this scene funnier if I cared even a smidgen about Derek's love life anymore. But, I don't.

Finally, the end of the day calls for a few drinks, and the doctors gather at Joe's bar. Addison, Callie and Erica are sipping wine and laughing at a table, and Callie appears like she is about to tell Erica about Addison's earlier inquisition when an intimate touch from Erica stops her in her tracks. The move doesn't go unnoticed by Addison, whose perception (and gaydar) seem to have improved greatly since moving to Los Angeles. McSleazy offers a dance to seemingly anyone in the room, and Callie (all too eager to prove her heterosexuality) downs a few shots and starts dancing.

While she shakes her groove thing deeper into the closet, Hahn can't take her eyes off her and calls her "beautiful" to Addison. (Am I dreaming, or did this scene really take place?)

The show closes with Izzie getting a report revealing that Ava isn't really pregnant, and Addison lets Meredith know how unhappy she is to learn that she and Derek have broken things off. Sadly, it looks as though Addison won't be returning again anytime soon.

Make sure to check out Sarah's take on the Callie-Erica developments in this article. Also, go here to see the Grey's Anatomy Moment 5/1 (all Callie-Erica) if you don't have time to watch the whole episode online.