To find a mineral necessary for their plans, the team travel into the wilds of Pennsylvania and discover an encampment of people documenting human history since the invasion.

The fight for freedom intensifies when the Fringe team revisits Walter's Harvard lab, which is now under the control of the Observers.

The Observers and the team engage in a battle in the year 2036.

After tracking a lead to a hostile and heavily guarded location, the team are reunited with Phillip Broyles, but doubt whether he can be trusted.

In 2036, Peter, Astrid, Walter, and Peter's daughter Etta search for Olivia, who holds the key to defeating the occupying Observers.

A devastating event leads to a strategy change before a key team member makes a pivotal and shocking move.

A team member turns their hand to a new role; Walter uncovers a key piece needed to defeat the Observers.

Elsa from Arendelle creates a powerful snow monster to protect her when she finds herself scared and confused in Storybrooke. Plus, Regina wonders if her relationship with Robin Hood is over.

Emma's life is put in danger by Elsa when they both get trapped inside an ice cave. Plus, Anna tries to teach a timid David to fight Bo Peep in the Enchanted Forest of the past.

The residents of Storybrooke blame Elsa when a chilling spell is cast on Marian, unaware the mysterious woman who is in charge of the town's ice cream parlour has the same powers as Elsa and is trying to frame her.

Before he goes on an important date with Emma, Hook asks Mr. Gold to reattach his hand. Plus, Will Scarlet attempts to break into the library to find a book, while Mary Margaret and Henry try to give Regina hope.

The Snow Queen's spell has the residents of Storybrooke at each other's throats; Emma and Elsa race to break the curse; Regina and Mary Margaret face off.

Mary Margaret and David rally the town to prepare for the impending curse, as Belle and the fairies work on an antidote; Gold works on an exit strategy; Emma and Elsa search for Anna.

The heroes pick up the pieces in the wake of the Snow Queen's spell; Regina must make a difficult choice; Gold's quest for power threatens everything he cares about.

In order to search for the Snow Queen, Regina joins forced and teams up with Emma. Plus, David and Mary Margaret prepare for their first date night away from the baby.

Belle tries to use the blade in order to get her husband to tell her where the Snow Queen is hiding. Plus, Belle travels to Arendelle to seek Grand Pabbie's help in recovering her lost memories.

The relationship between Robin and Regina grows increasingly more complex, as flashbacks show more information about the Snow Queen's life in Arendelle. Plus, Emma captures and interrogates the Snow Queen.

The Snow Queen tries to pit Else and Anna against each other, as Gold interferes with her plans. Plus, Emma seeks help from Gold when her powers spin out of control, while Regina's quest takes a surprising turn.

The Snow Queen attempts to pit Anna and Elsa against each other; with her powers out of control, Emma seeks assistance from Gold; Regina's quest takes a surprising turn.