'Harry Potter 20th Anniversary: Return to Hogwarts' Trailer: Emma Watson Tears Up Reuniting With Co-Stars

'We're family. We'll always be in each other's lives,' says Rupert Grint.

It was an emotionally charged reunion for Emma Watson. In the latest trailer for HBO Max's Harry Potter 20th Anniversary: Return to Hogwartsfans see the 31-year-old actress tear up as she reunites with her co-stars, Daniel Radcliffe and Rupert Grint, at the Warner Bros. Studio Tour London.

"It feels like no time has passed -- and loads of time has passed," Watson says, adding later, "When things get really dark, and times are really hard, there’s something about Harry Potter that makes life richer."

"It’s a strong bond that we’ll always have," Grint says while holding Watson's hand. "We're family. We'll always be in each other's lives."

The special also features other stars from the eight-movie series, including Helena Bonham Carter, Robbie Coltrane, Ralph Fiennes, Jason Isaacs, Gary Oldman, Tom Felton, James Phelps, Oliver Phelps, Mark Williams, Bonnie Wright, Alfred Enoch, Matthew Lewis and Evanna Lynch. Filmmakers David Heyman, Chris Columbus, Alfonso Cuarón, Mike Newell and David Yates.

Other moments from the trailer include Bonham Carter recalling to Radcliffe that her favorite scene from the franchise was in Harry Potter and the Deathly Hallows: Part 2, when she "had to pretend to be Hermione pretending to be Belletrix" as they break into Gringotts.

"I’ve still got the teeth," she reveals before putting them in, to Radcliffe's delight.

Additionally, Fiennes reveals that it was his sister and her Harry Potter-aged children who convinced him to play Voldemort. 

Harry Potter 20th Anniversary: Return to Hogwarts will begin streaming New Year’s Day on HBO Max.

For more with the beloved cast, check out the video below.