Shadowhunters' Jace and Clary will have to go their separate ways in the season finale.

Jace (Dominic Sherwood) is on a quest to take down his father, and the seasoned shadowhunter won't let his newfound sis join in the fight. That's all right, though. Clary (Katherine McNamara) has her own problems to deal with, namely tracking down the Book of the White.

We sat down with Sherwood and McNamara at WonderCon last weekend, and the pair dished on "Morning Star," the reasons behind the characters' temporary split, and the physically & emotionally draining missions that lie ahead.

"The mission your talking about is more serious, and it's the first one where Jace says to Clary, 'you're not ready for this. You're not Shadowhunter enough to come on this mission with us,'" Sherwood said of episode 13. "So it's an Alec and Jace mission."

In a staggering twist, Clary won't fight the elder hunter's decision.

"It's the first time Clary, essentially, listens to him," McNamara teased. "She's learned enough that she knows when he's serious and when to give him his space."

As you can see from the promo below, Jace and Clary will eventually windup in the same place. Valentine, however, will also be on hand, and Jace's temper might just get the best of him.

Check out the official episode summary:

"Jace, who is still reeling from everything that has happened, makes hunting down Valentine his number one priority even though he continues to wrestle with his conflicted feelings. In hopes of finding a way to stop Valentine before it is too late, Clary and Simon must find the key to unlocking Jocelyn's coma," Freeform teased. "But that key to unlocking Jocelyn's spell may just undo the Downworlder peace treaty, Simon's relationship with Raphael, and the Vampire clan in the process."

Are you ready for "Morning Star"? Catch the finale this Tuesday at 9 p.m. ET on Freeform.

Tags: shadowhunters television Freeform