Mitchell also talks with THR about Emily's plan to fight Sara Harvey and whether the Liars can trust Ezra.

In the midst of solving a murder case, Pretty Little Liars dropped another bombshell on Rosewood: Emily's (Shay Mitchell) health problems are self-inflicted.

During Tuesday’s episode, “The Gloves Are On," Hanna caught Emily injecting hormones into herself, prompting her to reveal she’s preparing to donate her eggs to make money.

After there was talk of cancer in the season premiere, this is a far less scary issue, but that doesn’t mean it will be an easy road for Emily. Star Shay Mitchell tells The Hollywood Reporter that after revealing the situation to the Liars — including an upcoming “one-on-one” moment with Alison (Sasha Pieterse) — she’ll use them as support while tackling bigger issues.

Below, Mitchell previews the potential “fight back” against Sara Harvey (Dre Davis), how she’s “questioning everybody” in the murder case — especially Ezra (Ian Harding), and how the new Big Bad is “scarier” than any others from the past.

Is Emily donating her eggs the whole truth, or is she using this as a cover-up for another secret?

You never know really ... but no — it’s true. This is what she’s dealing with right now. She was honest in the fact that she had no money, and this is her way of going about it.

What do you think Emily’s breaking point was in her decision to donate her eggs?

It was the fact that her dad had left her this money and she blew through it in California. Her mind wasn’t in the right place at school, and it was a lot harder for her than she ever could have imagined. To get quick, fast money, she must have seen an ad somewhere [for donating eggs] and got the idea.

Do you think her decision was impacted by the idea of assisting LGBT couples?

I think she would help any couple, but I can imagine Emily wanting to have a family of her own in the future. LGBT people have kids of their own and they adopt. She wanted to help whoever could benefit from having an addition to her family.

Emily has to inject hormones into herself often. How is her health affected by this?

I think when she was hiding it, it was harder. You’re going through ups and downs, almost like when females are going through that time of the month. You’re a little more emotional, and we saw that when she was more heated and jumpy with Aria [Lucy Hale].

Is Hanna (Ashley Benson) going to keep her secret, and are we going to see her open up to the other girls all at once?

I think in this case, Hanna will leave it up to Emily to speak for herself when she feels comfortable. It happens not too long after — she sits down with all the girls and gets it out there. She doesn’t want to do it alone and she doesn’t want to hide anymore.

Is there support from the girls, or do they try to talk her out of it?

Hanna asked Emily if she’s sure, and Emily really doesn’t mind because she wants to help someone else have a family. She knows what she’s doing at this point, and she gave it a lot of thought when she was deciding what she wants to do. I think the other girls will always be supportive, no matter what, and the beautiful thing about their relationship. They always have each other’s back, even though they may not always agree completely.

Does she have a one-on-one moment with Alison to talk about these issues, or in general?

There will definitely be some one-on-one time with Alison.

What’s going through Emily’s head with Sara? What does she want to do to stop her?

With age and five years the girls have spent apart, she’s come back to this with confidence. She just wants to quash things when they happen. It just annoys her, which is why she walks straight up to Sara. She wants to get to the bottom of this, she doesn’t want to be scared anymore, and she is ready to go head first.

Would she fight back?

If it gets to that point, she’s ready to fight back. Knock her out again! She is just like, “OK, what are you doing here, really? What’s your motive, what’s your plan, what’s going on?”

Do you think Emily would try to make amends with Sara to get her to smooth things over, or is she ready to fight?

I always think Emily is more of a lover than a fighter, but she’s also learned not to get taken advantage of. This is someone whom she got really close to and let stay in her house and then to see Sara’s other side, that was really heartbreaking for Emily. She was trying to get close to someone and open up again, and then she was a completely different person. She’s not trusting of Sara anymore, and there’s no way for them to be friends. But she does want to put an end to Sara stalking her. Does she feel guilty? A tiny bit. But Sara did deserve the left hook.

Does Emily think that Ezra killed Charlotte, or it’s all part of Sara’s grand scheme?

I think she’s questioning everybody. She’s questioning Sara and Ezra. Emily’s a lot smarter than we last saw her. She can put things together a lot quicker. As much as she’d like to give him the benefit of the doubt, he seems shadier these days. The girls go through their ups and downs with people they can trust, and they’re all trying to get down to the bottom of who left the hotel that night.

If you had to rank the Big Bads, is this new one scarier than Mona or Charlotte?

I think so. It’s getting more intense! I think [he or she] knows the girls are five years older and is really messing with them this time.

Does the new Big Bad go full force, is it a slow burn, or does it go up and down with threats?

I think it ebbs and flows, but the issues they’re dealing with now are a lot more mature. This new Big Bad is really like, “OK, you’re adults now. Game on.” It’s different than what we’ve seen before.

What do you think about Spencer and Caleb’s relationship?

It makes me happy. Even though Hanna is upset that she and Caleb aren’t together anymore, I think she wishes the best for him. I think he wishes the same for her. And if Spencer is who makes him happy, I think Hanna is genuinely happy for him. But it is crazy, and the scenes last night were very intense!

Pretty Little Liars airs Tuesdays at 8 p.m. on Freeform.