Interview: Linda Cardellini talks ‘Welcome to Me’ and keeping quiet about ‘Avengers’

“Welcome to Me” is filled with characters who stare slack-jawed at the things its lead character — Alice, a mentally unwell lottery winner played by Kristen Wiig in full awkward mode — does. The only one not horrified by Alice’s actions is her best friend Gina, played by Linda Cardellini. Though technically a comedy, which follows Alice as she uses her newfound riches to make a deeply weird TV show, the actress — famous for “Freaks and Geeks” and now on Netflix’s “Bloodline” — was most interested in how it blended tones, even making viewers care about Alice, even when she starts treating loved ones terribly.

Playing the straight man to very funny people can be very difficult, one imagines. Was it hard to not crack up and ruin takes?

Sometimes! It could be hard to keep a straight face. We did a 15-minute improv where she hides in the bathroom, and we just kept going back and forth, back and forth. But [Alice] is so heartbreaking. I don’t think the audience is ever laughing at this woman with mental illness. You’re laughing with her at certain times and feeling terrified and bad for her at others.

Gina plays an important role in grounding the movie, showing that Alice isn’t just a loner, but someone with real relationships.

The relationship between Alice and Gina is really fun. It’s like this platonic romantic comedy between the two of them. They come together and fall apart. I loved the way I was able to add meaning to the story for her.

Not all actors worry about backstory, but it seems important in this case to imagine a way they became friends.

We imagined that her mental illness didn’t totally surface until she was a little bit older. There’s a part of Alice that Gina knows that no one else really does, except for her family. That comes from being friends since they were little kids. They love each other very much. There’s a part of Gina that admires the bravery that Alice clearly has.

Mental illness can be a tricky subject to deal with in any film.

I was drawn to the idea that mental illness is hard for someone who has mental illness, but it’s also difficult for the people who are there for them. It’s hard to watch somebody go through something or be destructive toward themselves. The people who love them have a difficult time with that, because it’s hard to watch them be hurt or hurt themselves. [The film] doesn’t treat it as this quirky little problem. There’s a fine line.

The two tones are really intertwined here.

That’s something I really liked about “Freaks and Geeks,” that you can take something that’s serious and painful and show it in a way that people can relate to in a real way, but also in a way that people can laugh at it.

You actually suddenly pop up halfway into “Avengers: Age of Ultron.” Were you under lock and key not to reveal that?

Yeah. I didn’t even tell my parents and my family. Then it leaked on the Internet that I was somehow in it. I got a lot of heat for that from them. [Laughs]

I imagine you were probably used to keeping secrets from your stint on “Mad Men,” where Matthew Weiner was adamant about people not spoiling spoilers.

I don’t like spoilers either. After I was done with the show I was invited to be in the table reads. I would politely decline. I just love that show. I prefer to have things surprise me.

I have to admit I’ve never seen one of your earlier films, Dee Snider’s “Strangeland.”

[Laughs] My parents used to have that poster in their house, because it was the first poster I was ever on. It was strange because it’s such a terrifying poster. [Laughs]