Catherine and Elizabeth are about to lose it on Reign.

'Reign' Actor Jonathan Keltz Talks To Enstars About The Morbid Content On Series

In a promo released last Friday, Catherine is trapped downstairs when she demands to see the king since she is his mother. But the way she does it won't make her look stable in any way, shape or form. Mary realizes that Catherine will never give up on fighting for what she wants so it's probably best to keep her locked up. This leaves some curiosity on what this means for Mary as ruler and how far she'll go to keep the royal court safe.

Queen Elizabeth, on the other hand, is told that her life changed ever since her royalty was the main focus of who she is. Even though she has power, she feels like a prisoner. And she'll have moments where her insecurities truly come out and she doesn't know what to do with herself.

It's A Battle Of The Queens In The Third Season Of 'Reign'

Francis is still sick so Mary comes to the conclusion that maybe she could dispatch Catherine. In her perspective, this is for the best, but would Mary really go that far?

Adelaide Kane (Mary) previously spoke with Talk Nerdy With Us about what viewers should've expected as her character found out about the other ladies' evil plan.

"Francis and Mary are gonna find out eventually, and I imagine they are not gonna react...well," Kane said.

Check out the promo for the next episode below.

Reign airs on Fridays at 8 p.m. ET on The CW.

Tags: Reign television the cw