HBO Max debuted a new teaser for the upcoming retrospective special Harry Potter 20th Anniversary: Return to Hogwarts. The streaming event will reunite several key members of the Harry Potter film franchise—including lead trio Daniel Radcliffe, Rupert Grint, and Emma Watson—as they celebrate the 20th anniversary of the series’ first film, Harry Potter and the Sorcerer’s Stone.

The 50-second video teases the return of actors Robbie Coltrane (Hagrid), Matthew Lewis (Neville Longbottom), and Mark Williams (Arthur Weasley), as they each receive letters inviting them to join in the festivities. The letters are designed to resemble the ones that future students receive from Hogwarts School of Witchcraft and Wizardry in the books and films, offering them a seat to study magic at the institution. We are also shown a glimpse of Platform 9 3/4, which is where Harry and his friends board the Hogwarts Express.

Additional cast members joining the tribute special include Helena Bonham Carter (Bellatrix Lestrange), Ralph Fiennes (Lord Voldemort), Jason Isaacs (Lucius Malfoy), Gary Oldman (Sirius Black), Tom Felton (Draco Malfoy), James Phelps (Fred Weasley), Oliver Phelps (George Weasley), Bonnie Wright (Ginny Weasley), Alfred Enoch (Dean Thomas), and Evanna Lynch (Luna Lovegood), among others.

harry-potter-and-the-sorcerers-stone-harry-ron-hermione
Image via Warner Bros.

RELATED: What Is the 'Harry Potter' Cast Doing Twenty Years After 'Sorcerer's Stone'

The retrospective special “will tell an enchanting making-of story through all-new in-depth interviews and cast conversations” and will take fans “on a magical first-person journey through one of the most beloved film franchises of all time.” The Harry Potter series, which comprises eight films that were released between 2001 and 2011, is among the highest-grossing film franchises of all time. A spin-off series of five films, starting with Fantastic Beasts and Where to Find Them, is chugging along, with the third installment slated for a 2022 release.

Harry Potter 20th Anniversary: Return to Hogwarts is produced by Warner Bros. Unscripted Television in association with Warner Horizon at the iconic Warner Bros. Studio Tour London—The Making of Harry Potter. The special is executive produced by Casey Patterson of Casey Patterson Entertainment (A West Wing Special to Benefit When We All Vote) and Pulse Films (Beastie Boys Story) and will arrive on HBO Max on January 1.

You can watch the new teaser here: