's Best Performances series focuses on stand-out actors and actresses from the past year of television. Whether they made you cry, laugh or a mix of both, these are the performers — and characters — we won't forget, all year long.

CBS' Mom spends most of its time delivering zingers and great laughs. But every now and then, it surprises you with an intensely emotional episode. In Season 4, "Tush Push and Some Radishes" pulled off the balancing act between comedy and tragedy so beautifully that it snagged Allison Janney an Emmy nomination for Outstanding Lead Actress in a Comedy Series.

In the episode's opener, Bonnie (Allison Janney) and her daughter Christie (Anna Faris) are enjoying some girl time and learning to line dance. That light-hearted moment is called to a screeching halt, however, when Bonnie gets a call from a lawyer letting her know that her estranged mother has died.

The news of her mother's passing, coupled the realization that she'd kept a son after giving Bonnie away as a child, culminates in a pretty heartbreaking letter Bonnie reads at her mother's grave. She admits all the things she blamed her mother for, but also all the excuses she made for her own bad behavior because of her mother's abandonment.

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Anna Faris and Allison Janney, <em>Mom</em>Anna Faris and Allison Janney, Mom

"I have people in my life I haven't had closure with, or the relationships that I tap into that I have, that I would like to be better, or people I blame for things," Janney tells TV Guide. "The lesson that we learn in this episode — that Bonnie learns, that I continue to want to learn in my own life — is that it only ends up hurting yourself to hold onto things."

It's an intensely emotional moment, and it's no wonder why Janney got the Emmy nomination. It's a beautifully written scene, and Janney walks the line between anger and utter despair perfectly. Though she describes getting nominated as an "out of body experience" she's humble about the accolades and credits the material for inspiring her performance. "The writers just keep hitting it out of the park and giving us these great stories driven by these great characters that allow us to use all the parts of us as actors."

Additional reporting by Lindsay Macdonald

Mom premieres Thursday, Nov. 2 at 9/8c on CBS.

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