“Catch up on the story of the dragon cycle and prepare for Guild Wars 2: End of Dragons. Log in to Guild Wars 2 between May 25 and May 31 to unlock these spotlight episodes for free! Check your in-game mailbox for a letter containing story unlock tokens. You’ll find the unlocked episodes under “Living World Season 2” in your story journal tab, which is located in the Hero panel. If you’ve already unlocked the episodes previously, you don’t need the tokens—you’re good to go! New achievements for the episodes are available in the “Bonus Events” category of your achievements tab. You can complete these at any time to progress the Seasons of the Dragons meta-achievement and work toward earning legendary rewards.”
It looks as if the second and third episodes will roll out next week, fourth and fifth on June 8th, and the last two episodes on June 15th, so make sure you’re logging in to claim them.