Betrayal

The Magisterium arrives in the North to stop Asriel.

Lyra tries to get to Roger.

Lord Asriel opens a portal to a new world.

Lord Asriel tries to get Mrs. Coulter to join him in the new world; Asriel crosses.

Lyra and Will both enter a new world.

End Credits. (Edit: Unlike the rest of the season "Look at the Stars" is used as far as I can tell)

End Credits.