Perhaps more than any other series on television right now, This Is Us really knows how to pack an emotional punch. With countless twists, tearjerking storylines, and significant character departures already under its belt less than three seasons into its run, there's really no telling what more This Is Us is capable of producing in years to come - or how many more boxes of tissues viewers will find themselves desperately searching for.
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Before we get ahead of ourselves by starting to think about all the ways left that This Is Us can break fans' hearts, let's take a look back at some of the most emotional moments in the series so far. Tissues may be required.
Randall's panic attack
Randall Pearson is a man who always tries to act like he has everything together. But over the course of the series' first season, the cracks in the facade became quickly apparent. After all the stress Randall endured during this season, including connecting with his dying biological father, William, everything finally became too much for Randall, resulting in a truly devastating anxiety attack that left him stricken with fear and sobs.
Making the moment all the more emotional? Kevin, who hadn't always been the best brother to Randall, ran all the way from the theater he was set to perform at in order to be there for his brother after being able to tell something was seriously wrong on the phone.
Losing Kyle
The Big Three may be the heart of the entire series, but it's impossible to ignore the fact that the trio of siblings we know and love isn't the trio that Jack and Rebecca expected. The reveal that Rebecca had lost one of the babies in childbirth - a second boy, who would have been named Kyle - is a source of one of the series' most striking moments.
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After Dr. Katowski delivers the news to Jack, along with an inspiring speech about taking "the sourest lemon that life has to offer and turned it into something resembling lemonade," Jack is forced to share the news of the loss with Rebecca - resulting in a moment filmed with no sound at all, even as Rebecca sobs and screams.
Dr. K's backstory is revealed
Dr. K has served an important role in the series from the very beginning. As the man who brought Kate and Kevin into the world, and who convinced Jack that adopting Randall would be the right thing to do, his influence on the lives of the Big Three cannot be ignored.
Later in the first season, viewers are given an inside look at the life of the man who served such a key role in the Pearsons' lives - and what the series reveals is utterly heartbreaking. After losing his wife of over 50 years, Dr. K appears unable to move on with his life. He keeps the entire house just so, with all of her things in place, and even talks to her every day as if she were still there with him.
Jack reveals his drinking problem to Kate
Jack and Kate's relationship is one of the most crucial ones in the entire series. Kate was always close with her father, and even into her adult years, Jack's importance to Kate cannot be overstated, particularly in the heartbreaking way she blames herself for his passing.
But one of the most important, and most devastating moments the two share comes in a flashback to when Kate is a teenager, and Jack is struggling with alcoholism. Stressing that he never, ever wanted to let her down, Jack tearfully tells Kate of his addiction struggle. And Kate, surprising her father and causing him to break down, places her hands comfortingly on his face and wordlessly tells him that nothing has changed about the way she sees him.
Randall learns Rebecca hid William from him
Finding his biological family was a lifelong dream for Randall, no matter how much he absolutely loves the family who raised him. Even as a child, he searched high and low for African American couples who looked like they could have been his birth parents, and his emotional pursuit was something Rebecca was always aware of.
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This makes the reveal that Rebecca knew William, Randall's biological father, from when Randall was merely a baby entirely heartbreaking. When Randall confronts Rebecca about the truth, he's reduced to tears and disbelief and a total feeling of betrayal, telling the mother whom he adores more than anything in the world that he can't even look at her.
Kate's miscarriage
As soon as it was revealed in the second season that Kate was pregnant, fans were immediately anxious about it - and, as it turned out, rightly so. Given Kate's weight, any potential pregnancy would always be a risky one, and sadly, Kate miscarried. The second season episode "Number Two" chronicles Kate's struggle to accept the fact that she's not going to have a baby, while pushing Toby further and further away.
She takes it all out on herself at first, before lashing out at Toby, blaming him for getting her hopes up, before he tells her that she isn't the only one who lost this baby. The entire episode is utterly devastating from start to finish.
Jack comforts Randall about being different
From a young age, Randall has always been a gifted character, intelligent beyond his years and full of a seemingly endless font of compassion and kindness. In a season one flashback, Randall accompanies Jack to work and tries to downplay his intelligence. When Jack presses him about the matter, Randall breaks down, admitting that he doesn't want to be different than Kate and Kevin out of fear that they will resent him.
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Jack, clearly heartbroken by this reveal, immediately tells Randall to embrace what makes him, him, including all the differences and strengths he has. By the time he tells Randall "I love you as much as a human heart can, kiddo," there's no way anyone in the audience isn't sobbing their heart out.
Nicky reveals what happened in Vietnam
It's a mystery that has hung over the series for the last season and a half: what happened to Jack's brother, Nicky? The season three episode "Songbird Road: Part One" finally delivers the truth - and in many ways, it's far more heartbreaking than anyone could probably ever have anticipated.
Nicky is an old man living out in the middle of nowhere, having long since been cut off from his family, and not even aware of the fact that his big brother passed away. The source of the fracture? When serving in Vietnam, Nicky was responsible for the accidental death of a little Vietnamese boy, a tragic accident that led to him having a psychotic break.
William's passing
From the moment Randall and William shared a scene together in the pilot, it was immediately clear that this relationship was going to be something truly special. Over the course of the first season, the long lost father and son grew closer and closer, building the beautiful, loving relationship they'd never been able to have.
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The sixteenth episode of the first season, "Memphis," finds Randall and an ailing William taking a road trip back to William's hometown. But as heartwarming as their connection is on this journey, the episode builds to a heartbreaking conclusion: William knew all along that he didn't have much time left, and he wanted to be alone with his son when his time finally came.
Jack's passing
The mystery of Jack's death is one that plagued the series for much of its first two seasons. Viewers eagerly sought every clue they could possibly find as to what happened to the beloved Pearson patriarch. But it wasn't until the fourteenth episode of the second season that the truth finally came out.
After heroically saving the entire family, as well as Kate's dog, and some precious family mementos, from a devastating fire that destroyed their home, Jack suffered cardiac arrest as a result of smoke inhalation and died very suddenly. Mandy Moore's acting when Rebecca walks into the hospital room and, without knowing Milo Ventimiglia would be there, sees Jack's lifeless body further cements the absolute tragedy of the moment.