Harry Potter fans got a big surprise this morning in London. Gathered at the King’s Cross railway station for the annual “Back to Hogwarts” day (spoiler: it’s when the witches and wizards in the Harry Potter stories head back to school), they were greeted by two of the film stars from the Fantastic Beasts series.

Eddie Redmayne and Jude Law of the upcoming adventure Fantastic Beasts: The Crimes of Grindelwald (the second film of an anticipated five in the series), joined the fun at the annual gathering, which celebrates the departure on an ancient stream train to Hogwarts via magical Platform 9 ¾.

The annual gathering is a big moment for the U.K.’s Harry Potter fans. Each year on September 1st, they flock to King’s Cross by the thousands, often dressed as their favorite character from J.K. Rowling’s Wizarding World, to commemorate the day.

Fans lined up for hours at a popular photo point to get a shot of themselves pushing a luggage trolley “through” the brick wall to recreate Harry and others’ passage through the magical barrier and onto Platform 9 ¾, with staff on-hand to help with the finishing touches, such as their Hogwarts scarf.

Following a round of photos, the two stars led the countdown to the 11:00 AM departure of the Hogwarts Express.

In the upcoming film, Redmayne once again stars as Magizoologist Newt Scamander, with Law taking on the role of Newt’s friend and one-time professor, Albus Dumbledore, decades before he becomes Headmaster at Hogwarts.

The film is anticipated in mid-November from Warner Bros. Pictures. Beyond Redmayne and Law, the film features Katherine Waterston, Dan Fogler, Alison Sudol, Ezra Miller, Zoë Kravitz, Callum Turner, Claudia Kim, William Nadylam, Kevin Guthrie, Carmen Ejogo, Poppy Corby-Tuech, and Johnny Depp.

At the end of the first film, the powerful Dark wizard Gellert Grindelwald (Depp) was captured by MACUSA (Magical Congress of the United States of America), with the help of Newt Scamander (Redmayne).

But, making good on his threat, Grindelwald escaped custody and has set about gathering followers, most unsuspecting of his true agenda: to raise pure-blood wizards up to rule over all non-magical beings.

In an effort to thwart Grindelwald’s plans, Albus Dumbledore (Law) enlists his former student Newt Scamander, who agrees to help, unaware of the dangers that lie ahead. Lines are drawn as love and loyalty are tested, even among the truest friends and family, in an increasingly divided wizarding world.

Fantastic Beasts: The Crimes of Grindelwald was directed by David Yates, from a screenplay by J.K. Rowling. The film is produced by David Heyman, J.K. Rowling, Steve Kloves and Lionel Wigram. Tim Lewis, Neil Blair, Rick Senat and Danny Cohen served as executive producers. The film will be distributed worldwide in 2D and 3D in select theatres and IMAX by Warner Bros. Pictures.