The episode sets the stakes for the season: while the world celebrates a fragile peace, an ancient evil is stirring, and the clock is ticking for Viren to secure his permanent return to life.
The episode (Season 4, Episode 1 of The Dragon Prince ) marks the beginning of the "Mystery of Aaravos" arc, jumping two years forward from the Battle of the Storm Spire. The Return of Viren [S4E1] Rebirthday
For more details on the transition between seasons, you can check the official Dragon Prince website or read the episode breakdown on The Dragon Prince Wiki . The episode sets the stakes for the season:
prepares to welcome a delegation of elves to the castle, symbolizing a new era of unity. an ancient evil is stirring