Shadowhunters is finally back for its third season, and the mother of all evil is headed Clary's (Katherine McNamara) way.

The events of the Season 2 finale left several balls up in the air, one of which was the arrival of Lillith (Anna Hopkins), brought out of her hell dimension Edom by Jonathan (Will Tudor). Covered in what looks to be black blood, Lillith is definitely the most horrifying villain we've seen the Shadowhunters face this far.

She won't be the only problem Clary and the gang have to contend with though. Clary's wish from the angel to resurrect Jace (Dominic Sherwood) after he was killed by Valentine (Alan Van Sprang) will have both supernatural and political consequences in Season 3, and there's also that matter of the Seelie Queen (Lola Flanery) shoring up her allies in the Downworld to deal with.

It sounds like The Clave will have its hands full this season, so we called up Katherine McNamara to find out which problems will be a priority for Clary when Season 3 premieres.

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Where do we pick up in Season ? How much time has passed?
Katherine McNamara: There's been a couple of days I think, but not much time has passed since... we've seen Valentine's death on the beach and Jace's death and resurrection, if you will. And now Clary is receiving her Angelic rune and officially becoming part of the Shadow World, and diving head on into this life that she was once thrown into.

Where's Clary's head at after killing her own father and using the Shadowhunters' one wish to bring Jace back to life? Those are two really huge things to happen in her life.
McNamara: It's very true. A lot has happened to Clary. And from the beginning of the series, it's only been a few months if you want to think about timelines. So to go through all this, to be thrown into a new world, discover that you have these powers, lose your mother, your best friend becomes a vampire, you find and lose a brother, kill your own father, the love of your life dies and comes back to life, it's a lot. It's a lot to go through... She's gone from this little girl who looked at the Shadow World with a sense of wonder and magic to a woman who sees the world for what it is, which is a cold-cutting, dark, deadly world that has consequences for any seemingly harmless action. And she understands that now, and she understands that she has a responsibility to atone for everything that she's caused up until this point, and to fix any problem that's still occurring because of her.

Clary's finally, officially joining the Shadowhunter ranks, but she's doing so under terrible circumstances. She's hiding this huge secret from The Clave that she used their one wish. How long can she keep that up?
McNamara: You know, things only stay secret in the Shadow World for so long, and when there's one wish that's a failsafe for all Shadowhunters for all time and it gets used to bring your boyfriend back to life, there are some pretty dire consequences coming, let me put it that way. But what it does for Clary is it binds her and Jace together in the sense that they know that when the consequences come, it's going to be the two of them that are held responsible, and they have to be there for each other, and they have to be completely on the same page. But also, Clary feels the responsibility for what Jace is going through because she knows something's wrong with Jace. As much as he tries to hide it from her and put on a brave face, she knows that there's something going on, and she knows that she's responsible.

Emeraude Toubia and Katherine McNamara, <em>Shadowhunters</em>Emeraude Toubia and Katherine McNamara, Shadowhunters

Like you mentioned, Jace is suffering some serious side effects from the wish. How does that impact Clary's relationship with him?
McNamara: She's always seen Jace as this powerful, angelic warrior, and he's come back from this broken. And she feels responsible for breaking that powerful spirit that is in him, and what it does is because she can't turn to anyone without making them culpable, is it inspires this wonderful initiative in her to really take matters into her own hands and to handle things in a way that she will finally take responsibility, and she will finally forge her own way into the Shadow World and really take action in a real way.

It seems like this might be a major obstacle for them?
McNamara:
It's true. There's a huge block in their relationship at the moment, unfortunately. This is the first time that the two of them have had a chance to really let their relationship grow... and for them to love each other the way they've always wanted to. So moving forward, yes, you do see a few moments of light romance and a few times where they can actually behave as a couple without dealing with the world ending around them. But it does put a damper on things because they feel the weight of this secret and they feel the responsibility, and Jace too is struggling with these hallucinations that he's having that are rather violent, if you will.

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Alec (Matthew Daddario) is obviously very suspicious because he felt that Parabatai bond disappear. How's he going to feel knowing Clary and Jace are hiding something from him?
McNamara:
It's kind of an unfortunate situation. More than kind of an unfortunate situation. Alec has not trusted Clary for so long, being the new one coming in, and she's really had to prove herself to him. And finally, he's starting to accept her as a Shadowhunter, and they've really started to become friends, and he started to give her responsibilities and see her as part of the team, but now there's this secret, and it's really putting an obstacle in their way. Alec being Jace's Parabatai of course knows there's something going on, even if he doesn't know what it is, he knows. And Clary was the only other person on that beach, so obviously she's the one with the answers, and she can't lie to him very well because she sees how much it's hurting him and she sees how painful it is for him to know that his Parabatai is struggling and not know how to help him. Ultimately, she's stuck between a rock and a hard place because she can't tell him. She can't turn to Alec. She can't turn to Isabelle because it will make them culpable as well, and she refuses to let anyone else be hurt because of what she did.

We got our first look at Lilith in that trailer, but what can you say about her agenda and what she's planning?
McNamara:
Lilith is probably the most fierce evil that we've seen emerge from the shadows here. We've seen demons, we've seen greater demons, we've seen rogue vampires and evil Shadowhunters, but we have yet to see a Queen of Hell. We have yet to see the Mother of all Demons, and she is quite a fearsome foe. And also, Jace and Clary in particular have a huge target on their backs because Lilith — the closest thing Lilith had to a child was Jonathan, and we're responsible for hurting him. She's out for vengeance, and to put it lightly, forgiveness and reconciliation are not high on Lilith's priority list.

Lillith sort of alluded to maybe trying to bring Jonathan back to life. How do you think Clary would react to that if by some miracle he did come back?
McNamara:
This is the one dilemma with this relationship. The relationship with her brother is the one that has been left unresolved up until this point, and she will always feel his loss, and she will always feel that hole that's there because it's a relationship that never got given a chance... We saw that last season that as soon as she found out that she had a brother, and that Jonathan was alive and that he was out there somewhere, the first thing she wanted to do was find him and help him because to have that chance at finding a blood relative, to have that chance at having a piece of your biological family still alive and still there for you, of course you're gonna want to push through that ... I don't know, all I can say is that it will always be something that she feels responsible for and feels like was a missed opportunity.

Shadowhunters Season 3 premieres Tuesday March 20 at 8/7c on Freeform.

Dominic Sherwood, <em>Shadowhunters</em>Dominic Sherwood, Shadowhunters