Adelaide Kane & Toby Regbo: New 'Reign' Tonight!

Adelaide Kane, Megan Fellows and Toby Regbo greet a visitor in the castle in this still from Reign.

In “Left Behind,” Mary (Kane) and Francis (Regbo) are forced to rely on one another when the castle is taken hostage, and Catherine (Follows) shocks everyone when she makes a surprising proposal to try to save their lives.

Meanwhile, Bash’s mother Diane (Anna Walton) tells Bash (Torrance Coombs) of her plan to have him legitimized.

“Left Behind” airs Thursday, December 5th @ 9PM ET/PT on The CW.