The Harry Potter reunion special Return to Hogwarts, marking 20 years since the first film adaptation of JK Rowling’s gamechanging and multi-multi-million-selling fantasy series about the boy wizard was released, hews as closely to the original’s aesthetic as possible from the off.

Chats among the three main stars, Daniel Radcliffe (Harry himself), Emma Watson (Hermione Granger) and Rupert Grint (Ron Weasley), take place in the Gryffindor common room, there’s an opening set piece in the Hogwarts dining hall, Radcliffe and director of the first two films, Chris Columbus, talk in Dumbledore’s office and so on. It provides a rush of nostalgia only heightened as the enduring affection among them all becomes evident. There is much – rising perilously if perhaps inevitably close to emetic levels – of the cast and crew being like a family. There always is in programmes like this, but at least here it is more than usually justified. The actors famously began working on the franchise when they were children, and their audience grew up alongside them pretty much in real time as the films were released between 2001 and 2011.

The retrospective sees stars Daniel Radcliffe (Harry Potter), Emma Watson (Hermione Granger) and Rupert Grint (Ron Weasley) tell behind-the-scenes stories with in-depth conversations and interviews from the set of Hogwarts at the Warner Bros Studio Tour London - The Making of Harry Potter.

Other cast members from the franchise will also be involved, including Robbie Coltrane (Rubeus Hagrid), Ralph Fiennes (Lord Voldemort), Helena Bonham Carter (Bellatrix Lestrange), Gary Oldman (Sirius Black), Imelda Staunton (Dolores Umbridge), Matthew Lewis (Neville Longbottom), Jason Isaacs (Lucius Malfoy), Tom Felton (Draco Malfoy) and many more.