‘Reign’ Season 4 Spoilers: Series Finale Synopsis Released; Watch ‘All It Cost Her’ Promo

After four seasons of drama, death, love and heartbreak, The CW series “Reign” is coming to an end. Although most series finales send the characters off with hopes of optimistic futures, history tells us that the end of this show may not offer that to Mary.

“In the series finale, Mary (Adelaide Kane) changes the course of history with a decision she makes, and her perilous move for survival causes her to have a stunning realization,” the synopsis for “All It Costs Her” teases.

READ: The CW cancels “Reign” after four seasons

In the promo for Season 4, episode 16, Mary can be seen asking Bothwell (Adam Croasdell) where her child is to which he reassures her they will find him. In the last episode, Mary gave birth to the heir and the newborn was last seen in the nursery which also happened to be visited by his father, Darnley (Will Kemp).

There’s a good chance that while with his father the boy could be in danger. Darnley has syphilis and has been hallucinating to the point where he has been seeing his dead lover Keira (Sara Garcia) who has been talking to him. Could she have told him to take his baby?

In the promo for “Reign” Season 4, episode 16, a baby is seen lying on the ground, wrapped in a blanket as a man walks away from it. Could Darnley have left his son to die?

Mary can later be seen yelling, most likely addressing nobles reminding them that she is their queen. Could she be asking them to carry out an unforgivable act against Darnley? According to history, Darnley was murdered several months after his child’s birth and many speculated that Mary was involved with the gruesome crime. How far is she willing to go to save her child?

In the promo for “All It Costs Her,” there are also flashbacks of Mary’s time with Francis (Toby Regbo) spent in the French court. Could Mary’s decisions for her future be based on the years she had with Francis?

“Meanwhile, Elizabeth (Rachel Skarsten) steadies herself for war and becomes the instigator in Mary’s demise,” the synopsis for The CW series says.

In the promo, the Queen of England can bee seen dressed up in armor as if she is a soldier. “ I am England,” she can be heard saying as one ship, likely from England, heads toward another ship. Will Elizabeth start a new war that leads to Mary’s downfall?

Historically, part of the reason Mary lost her crown was due to speculation that she was involved in her husband’s murder and made no attempt to prevent it. It also didn’t help that not long after his death, Mary and Bothwell married and the two were later accused of murdering Darnley.

While Bothwell was found not guilty, Mary’s trial ran longer but she was never convicted. She was imprisoned instead. The royal eventually traveled to England and sought protection from her cousin Queen Elizabeth but was instead imprisoned for 18 years.

When Elizabeth found out that Mary was corresponding with a man who was plotting to have her removed from the English Throne, she held a trial where her cousin was found guilty of treason.

READ: Will Queen Elizabeth invade Scotland on “Reign”?

After signing a death warrant, Mary was executed at 44 years old. Although it is unclear if viewers will get to see that part of history take place in the last episode, it seems like there will be plenty of drama and tears as the characters of the show grace the small screen for one last time.

The series finale of “Reign” airs Friday at 9 p.m. EDT on The CW.