Eddie Redmayne and Jude Law surprised 'Harry Potter' fans at Kings Cross Station in London on Saturday (01.09.18), as part of the "Back to Hogwarts" celebrations.

Jude Law and Eddie Redmayne at King's Cross

Jude Law and Eddie Redmayne at King's Cross

Hundreds of fans of the magical franchise flock to the London train station on September 1 each year to mark the day young witches and wizards make their way to the mythical Platform nine and three quarters to board the iconic Hogwarts Express steam train that takes them off to Hogwarts School of Witchcraft and Wizardry.

And on Saturday, as fans gathered at the platform, Eddie and Jude - who star in the upcoming 'Harry Potter' spin off movie 'Fantastic Beasts: The Crimes of Grindlewald' - made a surprise appearance to join in the festivities.

Fans - many of whom dress up in their Hogwarts robes for the event - lined up for hours at the popular photo point to take a snap of themselves pushing a luggage trolley "through" the platform wall that whisks wizards and witches away to Platform nine and three quarters.

Whilst there are usually staff members on hand to help set up the photos, fans were shocked when they reached the front of the line to find that the staff this year were none other than Eddie and Jude themselves.

Eddie, who stars as Newt Scamander, and Jude, who plays a young Albus Dumbledore, then led the countdown to the 11am departure of the fictional steam train.

Whilst Jude, 45, is starring in the franchise for the first time in the upcoming movie, 36-year-old Eddie is reprising his role as Newt after first starring in 2016's first instalment of the spin-off series, 'Fantastic Beasts and Where to Find Them'.

'Fantastic Beasts: The Crimes of Grindlewald' hits cinema screens on November 16 this year, and also stars Johnny Depp as Gellert Grindlewald.