While there are still tough times ahead, it sounds as though she wont be going through them alone.

Youre going to see more Eve.

You get a lot of the ladies fighting against said evil evil Eve, McGrath tells EW.

All About Eve

Bettina Strauss/The CW

I think you get more understanding of where Eve is and how she got there.

In trueSupergirlfashion, they dont give you a cut-and-dried villain.

I dont think Eve Teschmacher is any different from that.

But she wont let that guilt get her down.

This has happened again to her.

So much of the world is dealing with the results of her actions again.

So she becomes very focused to fix it, and a focused Lena is a force to reckoned with.

Hes just been talked about.

Our first two days were all just me and Jon Cryer, just full scenes.

The first day was all him being sick with cancer.

So, it was just us in a lab trying to figure all of that out.

How did you feel playing that moment?He had me in tears.

I was weeping down my face.

We didnt do that [scene] many times because I was crying so much.

He really [shows] all of these very different sides.

Maybe theres hope for him.

Maybe were going to see a Lex Luthor that might be a hero.

But I think thats whats so wonderful about having an actor of Jon Cryers stature on the show.

One of the biggest twists is that Eve has been working with Lex the entire time.

Were you surprised when you found out?I was over-the-moon excited!

It completely turns the character as you accepted her on the show on its head.

Lena was basically doubly betrayed in that moment.

How does this affect her going forward?

Her drive and her focus to fix this is sort of second to none.

Two years later, we find out that even Lex knows her secret.

I think she needs that.

In doing that, she wasnt aware of the long-term effects of what it was going to do.

Its obviously quite massive and life-changing.

Lexs scheming pushes Lena to join forces with Supergirl and Alex.

They both believe in helping people and the greater good and saving mankind, which are all lofty goals.

Honestly, sitting here half in my pajamas talking about saving mankind is a good day.

But I digress).

Supergirlairs Sundays at 8 p.m.

ET on the CW.