Let's start at the end of Season 7's 22nd half-hour “Good Crazy” because that's when the only thing of consequence happened: After contriving to send her overbearing hubby off to Atlantic City with Barney, Lily settled in on their couch to enjoy a little personal time and the big bag of cookies that Barney baked for her. But wouldn't you know it? The enormous Ericksen spawn gestating in her uterus picks that exact moment to enter the world. But when Lily tries to reach Marshall and inform him of the momentous news (and get him to accompany her to the hospital) she only reaches his voicemail. That's because the big lug made the unwise decision to listen to Barney and shut off his phone for a full hour to concentrate on getting blotto drunk. With Marshall out of reach, Lily calls on Robin instead and her pal/quasi-lesbian crush comes rushing over, bumping into Ted along the way -- the first time they've occupied the same personal space together since that whole “Should we be a couple again or not... oh I guess not” thing a few weeks back. The last we see of them, they're standing in front of MacLaren's and here's hoping that Ted doesn't keep Robin tied up for too long with his naval-gazing because there's a pregnant woman upstairs in dire need of assistance. Won't someone please think of the (about-to-be-born) children!
Back up a bit and we see why Ted's so eager to speak to Robin in the flesh -- he's spent the past few days projecting her features on practically every person he's had a conversation with, from the MacLaren's bartender to the trio of girls that Barney set him up with as an after-Robin palette cleanser. They'll be chattering away while Ted pretends to listen and then all of a sudden, there's Robin! He's not exactly subtle about hiding the fact that he's experiencing these hallucinations either; when he's not blurting out things meant for Ghost Robin's ears, he just sits there staring into space, carrying on a mental conversation with his unseen-to-others ex. She's like the disembodied voice of Daniel Stern to Ted's Fred Savage. We can only imagine how unnerving it must be for those poor women to have Ted staring vacantly at them all evening. Hell, for that matter, it must be unnerving when he stares at them with purpose. Some people in this world just have unpleasantly weird faces and Ted Mosby -- along with Renée Zellweger, Carrot Top and the Fox & Friends crew (particularly the squinty-eyed dude who's not Steve Doocy) -- is one of those people.
Back up even further and you get Barney's pre-Atlantic City plot, which once again involves him having all sorts of conflicting feelings about the fact that he's dating a stripper. This time, he's even more conflicted than normal because Quinn keeps bumping into her clients on the street and, rather than averting their gaze and pretending to be immersed in another rousing round of Draw Something on their iPhones, they actually come up and talk to her, which is only slightly less weird and improbable than everything else that happens in this episode. Finally pushed past out of his enormous comfort zone, Barney decides to make an honest woman out of Quinn by offering her a (fake) job at Goliath for the same amount of money she makes by stripping, plus dental. But because the show now firmly takes place in Fantasyland, Quinn propagates the myth of the happy stripper, insisting that she's already got her dream job and going on to imply that Barney's job is the shameful one since “you people [i.e. bankers] are whores.” And while she's not entirely wrong about that, bankers do have the advantage of being able to commit their illicit acts while keeping their clothes on.
Back up further still and we're at the very beginning of the episode, with Marshall cradling a watermelon as if it's a newborn, Barney getting Ted hooked up with an online dating service and teaching him about the concept of “Condolence High Fives” and then Ted and Robin arriving at Lily and Marshall's baby shower absurdly late and absurdly early respectively in order to avoid seeing each other. And now it's over! Gee, that went a lot faster in reverse... although 95 percent of it was still just as pointless.