After close to two months off, "This Is Us" jumped right back into action with Tuesday night's new episode, "Light and Shadows." Romance! Danger! Medical drama! Secrets! A new episode of "World of Dance" on the DVR! Truly last night's return had it all, cramming a lot of plot development in a single episode but navigating it all well without making one character feel too forgotten.

So let's talk about all of that plot development. Here are the five things you need to know about the return of "This Is Us" last night:

1. The diagnosis is in for Rebecca 

Last we checked, Rebecca was in a bad place, forgetting things in the present – and seemingly forgetting just about everything in the future, lost even while surrounded by her loved ones. (Well, most of them; in a rarity for "This Is Us," it seems pretty obvious where this storyline is going for the Big Three.) And now we officially know why, thanks to a doctor's visit arranged by Randall with the help of apparently about 47 pestering emails. The diagnosis: She has mild cognitive impairment, with the potential for further mental degradation very likely in her future. 

The good news is that Rebecca isn't entirely gone yet; the tests show that, while her brain is struggling and making errors, she's still got some grasp on reality. She makes small errors and accidents trying to remember sentences as opposed to totally spacing on them, and while her hand-drawn clock is sloppy and shows signs of spacial struggles, with many numbers crammed together at the end, at least it still resembles a clock. But things are definitely not trending in the right direction, and now Rebecca knows it, which props to Mandy Moore for some excellent silent acting tonight, quietly realizing that the moments that meant so much to her throughout her life – like getting Jack back during the flashbacks after he breaks up with her due to her dismissive father's attitude, the storybook romance that ensued over the years and even merely watching early morning sunrises with Randall as a baby – will slowly leave her. I'm not looking forward to watching that at all!

I'm also not looking forward to seeing the fallout from this – and not just for Rebecca. As I alluded to earlier, this is the rare storyline for "This Is Us" that seems pretty obvious about where it's going: Randall is going to get in trouble with Kate and Kevin for staying mum about their mother's mental health, and that's why Randall wasn't in that flash forward from the previous episode – and why Kevin said they weren't talking anymore. So that's going to suck, too. In general, not a lot of good news in this storyline. But at least Rebecca and Jack got back together in the flashbacks, which as we all know ended happily ever with no crockpot-related traumas whatsoever! Damn you, "This Is Us"!

2. Brooke Davis wastes Kevin and John Legend's time

Kevin's had quite the tortured love life – and Tuesday night's episode added yet another trip to the emotional rack. Last we left Kevin, he realized he wanted to be a father and wanted to focus on finding his special person in life – but even with a matchmaker (or was it just an app?) things weren't particularly promising. His first date was with a woman way too intelligent and level-headed to be dating The Manny. The second date was with a racist. Suboptimal!

As is the mysterious ways of love, though, as soon as Kevin starts relaxing and deletes the matchmaker – and I mean WITHIN MILLISECONDS of deleting the app – he meets seemingly the one: Lizzie, played by "One Tree Hill" star Sophia Bush. She gives him sexy eyes from across a coffee shop. She's got a great dog named Adrian, inspired by "Rocky." She loves peanut butter M&Ms drizzled on top of movie theater popcorn. And, most importantly, she's seemingly a notable enough actress that she would possibly be around for a number of episodes. So yes, I was predicting that these two would be getting down to business before episode's end – especially when the show busted out the audio aphrodisiac that is John Legend's voice for a hastily arranged surprise romantic concert. What, she's flying back home to Chicago? Considering Kevin's dating history, long-distance would be essentially a breeze!

Unfortunately, even the sultry sounds of an EGOT winner can't make this work as, in the midst of their private performance, Kevin discovers that Lizzie is actually married and that he's merely her "hall pass" celebrity. Welp, time to cut the set short, John.

Kevin heads off to reshoots for his M. Night Shyamalan movie – remember that?! – where he complains to poor Noah the production assistant who just wants to get Kevin on set and instead gets an entire rant about sad romance. But unbeknownst to Noah the PA, he's holding some big news in his hands as Kevin tosses him his phone while he's filming – and the phone reads that Sophie is calling. It seems only fitting that in an episode featuring Jack and Rebecca fighting through struggles and even a short breakup to have their "love story for the ages" that Kevin and Sophie would add a new, and perhaps final, chapter to their version as well. 

3. A new direction

Generally speaking, the visuals on "This Is Us" tend to go unnoticed. Not that the show ever looks bad, but it's never particularly the focus, the direction instead leaning more toward guiding the performances to where they need to be as well as getting out of the way of the emotions and the show's famously complex story structure.

"Light and Shadows," however, felt slightly different. You could tell somebody new was behind the camera – which turned out to be true and false at the same time, as Tuesday night's episode came courtesy of Yasu Tanida, indeed a first-time director for the show but also its regular cinematographer for almost 70 episodes. And he didn't miss his chance to make his mark, however subtle, as the guiding hand behind a whole episode.

While still impressively weaving the episode's MANY storylines together in a way that made none of them feel particularly short-changed – notoriously a problem for "This Is Us" – he added some unexpected transitions to the proceedings, mainly when moving to and from Rebecca's storyline. The world would blur before slowly, dreamily coming back into focus. It's a seemingly modest stylistic tic, but one that actually added a lot to the episode, bringing the audience into Rebecca's growingly hazy and elusive mind and adding a warm yet almost unsettling vibe to the show's familiar sense of past, present and future smearing together, informing and impacting one another.

Again, it's not like "This Is Us" turned into "Hannibal" or "True Detective" for a night – the star here is still the heavy emotions and intricate structure, not the visuals – but just those small unexpected choices made a difference and made me excited to see what Tanida might do next. 

4. Toby and Kate are not long for this world

Kevin wasn't the only one having an emotional yo-yo of an episode when it comes to relationships, as Toby and Kate went through a roller coaster of feelings – with a crash seemingly inevitable. 

Last we checked, Kate accidentally caught Toby texting a mysterious CrossFit lady pal about his recent struggles with Kate. Right after Thanksgiving, he tries to explain that it was just a vent session to some friends and nothing serious, and while the two move forward from there, things still seem forced at best and frosty at worst. Things improve over time, but just when life seems to resemble normal, Kate discovers at a Jimmy Buffett birthday party for Toby that while he's been jetting out of the house every morning for his workouts, he actually hasn't been to the gym in weeks. DECEIT AND LIES! Toby tries explaining that his mysterious female CrossFit friend tried to kiss him but he dodged it and even transferred gyms – but in the hopes of not causing more problems, he kept the whole situation to himself instead of telling Kate. Which, of course, ACTUALLY caused more problems. 

But, as Kate tells Toby, she'd actually prefer if he was cheating. At least that would give her a logical reason why he seems like he's distancing himself from their family. Now she's stuck with the same question she's had for a while: Why does Toby seem so different? Well, Tuesday night, she got an answer: Jack Jr. being blind makes Toby sad. While Kate still views their son with joy and promise, Toby just sees the negatives and the struggles – perhaps this is due in part to his depression, which the show touched on in the past.

The episode nudges toward a happy ending at the very end, with Kate discovering that Jack Jr. can at least see vague light and shadow, giving him some semblance of vision and giving Toby a brief bit of happiness and hope. But Kate clearly isn't happy – and she definitely seems like she's not secure in Toby being there for her or their son when the times get rough. At this point, I'll be amazed if they're still together through the end of the season – but then again, Randall and Beth seemed destined for Splitsville last season too, and everything's fine with them now. OK, maybe not fine because ... 

5. A rough night for Randall

Somehow confirming that his mother is literally losing her mind was just the start of Randall's bad night.

First of all, during the doctor's visit, he had to deal with an uncharacteristically snippy and bitter Miguel, who seemed upset at Randall for aggressively taking the reins on his wife's mental health – but maybe more so upset at himself for not noticing the problems that seemed so clear and obvious to her son. By the end, he admits to Randall that it was the latter, that he felt awful for indeed recognizing that something wasn't right but not wanting to admit this new reality to himself and took his denial out on Randall. Still, it was surprising to see Miguel, usually the fairly level-headed one in the clan, become such a surly canker sore. I guess he just really didn't want Randall getting in the way of the "World of Dance" episode they DVRed (which, NBC, please dial back the in-house product placement).

But again, somehow that was still the better portion of Randall's night. In the big final reveal, Randall arrives home and visits everyone in the house: Beth, Tess, Annie, Deja ... oh, and the unknown burglar creeping around in the kitchen with what looks like a knife. SO THAT'S NOT GOOD AT ALL! Obviously this isn't the end for Randall – we know he must be alive in the future for Kevin to be giving him the silent treatment, much less to be grey-haired in the far-off future for Rebecca's final days – but I was very much looking forward to Randall being able to sleep off his tough day. And I was very much looking to ME being able to sleep too, but that's gonna be a little difficult knowing "Randall gets shived" is a distinct possibility in next week's episode.