Delicate Timing — When Does Cathy Tell Adam About Her Diagnosis in 'The Big C'?

Discovering that you're facing a terminal diagnosis is the kind of life-changing moment that can shift everything in your world. Not only do you have to adjust the way you expect and envision your future, but it also changes the lives of people around you in a ripple effect.

In Showtime's streaming television series The Big C, protagonist Cathy takes viewers through her journey.

Cathy is faced with the questions so many people have to answer: When do I tell my loved ones? How do I come to terms with this? What do I do next?

As she begins to grapple with these questions and make forward steps on her journey, we see her share her cancer diagnosis with several important people in her life. But when does she tell her son, Adam? Here's a look back at the difficult decision she made.

Cathy, played by Laura Linney, has no easy answers to her questions. As a high school teacher living her life in Minnesota, Cathy suddenly has to face her mortality after a diagnosis of Stage IV melanoma.

Part of that challenge involves when she should tell her high school-aged son, Adam (played by Gabriel Basso).

Cathy's diagnosis makes her realize that she needs to change the way she's been parenting Adam. He can no longer just live life like a carefree teenager; she needs to impart some important lessons, and she needs to do it now.

But even so, she holds off on telling Adam until the season finale of Season 1: Episode 13.

Like most teenagers, he struggles with the sudden realization that he's going to lose his mom. Their complicated relationship makes a difficult moment even tougher, and Adam seems to be emotionally numb and frustrated in turns (via Big C Fandom).

It likely isn't until after Cathy passes that he comes to terms with just how big of a loss he suffered. Luckily, he manages to put in the work to get his high school degree, giving Cathy a measure of comfort and pride as he achieves her dream for him.

And then, of course, there's her husband Paul (played by Oliver Platt). Paul is hurt by Cathy's affair and desperately wants to heal their relationship. But for most of Season 1, he has no idea that Cathy is battling something larger than the both of them.

In Episode 1 Season 10, Cathy finally tells Paul the truth. Unfortunately, both Paul and Cathy have been lashing out at one another and turning to others for solace.

After Paul discovers the truth, they still have to navigate the complex ups and downs of a marriage in shambles.

The Big C doesn't shy away from showing the very human failures and struggles that people face, even when cancer is looming over the whole family.

But once Cathy has revealed her diagnosis to both her son and husband, they have to embark on a new journey together.