Mary & Elizabeth Drastically Age in 'Reign's Series Finale

Rachel Skarsten is giving us all the goodies for tonight’s series finale of Reign.

The actress, who plays the “Virgin Queen” Queen Elizabeth I, revealed that both she and Adelaide Kane were aged for the final episode.

In the finale, titled, “All It Cost Her…”, Mary makes a decision that will change the course of history — forever shaping the fate of her nation, her crown, and her newborn son.

Mary’s perilous move for her survival causes the stunning realization that perhaps she is not the only one who may not survive.

Meanwhile, Elizabeth steadies herself for war and will become the instigator in Mary’s demise while later realizing she and Mary might be more similar than either thought.

Tune in TONIGHT @ 9PM ET/PT on The CW.