On the latest episode of "Reign," Henry's craziness reaches new heights and Lola discovers a huge secret.

In "Long Live the King," Francis (Tony Regbo) returns home with Mary's (Adelaide Kane) uncle, the Duke of Guise.

King Henry (Alan Van Sprang) then announces that the Queen of England has died, and it is now up to Mary to declare her claim to the throne.

After having a romantic time with her husband, Mary writes her cousin Elizabeth a letter asking for peace.

Elizabeth doesn't read her cousin's letter, and it ends up in her uncle's possession.

One of Catherine's (Megan Follows) spies then finds out that Henry is planning to invade England at the end of the week.

Catherine and Mary have a secret meeting, and come up with a plan to kill the king. But Francis convinces them to give him one last chance to get through to his mentally ill father.

While on a hunting trip, Francis learns that Henry and his brother were captured by the Spanish and put through three years of torture. Francis feels for his father, and eventually convinces him to postpone the invasion of England.

Later, a mysterious man tries to kill Henry, but Henry is able to kill his attacker. Mary, Francis and Catherine find out the Duke of Guise hired the mercenary to kill the king.

Meanwhile, outside the castle, Bash (Torrance Coombs) is hunting The Darkness when he comes across a young boy. He tells Bash and Kenna (Caitlin Stasey) the town where The Darkness resides.

At Lola (Anna Popplewell) and Julien's, Julien's uncle arrives to reveal a big secret: Lola's new husband isn't Lord Julien at all. It turns out Lord Julien died in a fire, and he is really Remy, Lord Julien's personal secretary. Remy was holding Julien's crest when he was mistaken for him, so he decided to assume the fallen lord's identity.

Remy then gets into an argument with Julien's uncle, and the uncle gets accidentally stabbed by a sharp-cornered object, instantly killing him.

Lola decides to fake Julien's death by burning the house down so he's not implicated for murder. Julien decides to go on the run, and she says she'll return to court.

In the end, Henry says that he wants to take England, but first he wants to kill his son, Francis, and marry his son's wife.

On the upcoming season finale, "Slaughter of Innocence," "Mary and Francis take drastic action in response to Henry's madness. Meanwhile, a terror in the woods puts everyone in peril; and Mary makes a bold choice when she discovers Lola is in the midst of a life-threatening labor."

Watch the promo below for the season finale, which airs Thursday, May 15 at 9 p.m. on The CW.