Distinguished British actor Jim Broadbent was very much the new guy on the set of the latest Harry Potter film.
Jim Broadbent contemplates his favourite scene in the latest Harry Potter film
He joined a cast that grew up together on five previous instalments of the huge franchise.
The 60-year-old Oscar winner plays Professor Horace Slughorn, a sycophantic former Hogwarts teacher who is persuaded to return to Hogwarts School of Witchcraft and Wizardry, as part of a plan to defeat the evil Voldermort.
Broadbent, who won his best supporting Academy Award for playing the husband of author Iris Murdoch in Iris, said he had few qualms about joining the cast.
"I knew [producer] David Yates before, had worked with him and loved him, so that's where the invitation came from.
"I loved the films anyway, they're great and the character was irresistible, so it was a no brainer really, no apprehensions."
He admits he read the first Harry Potter book when it was published in 1997 and the outing the current film is based on, but none of the others in between, leaving great gaps in his Potter knowledge.
"You put it altogether, I'm sure there are bits I still don't understand but not wholly necessary for me to know," he says.
Slughorn plays favourites with his pupils
The on-screen Professor Slughorn is a weasly character who boasts of teaching the most gifted students to have passed through Hogwarts through the years.
Broadbent delved back into his schooldays to mould his character.
"He's a teacher and we've all had teachers. I was at a public school that was not quite the same as Hogwarts," he explains.
"But there was enough I could draw on to pick up on various characteristics of some of my old teachers, and that's certainly where I first went for inspiration."
The main trio of actors - Daniel Radcliffe, Emma Watson and Rupert Grint - began their Harry Potter journeys at a very young age.
Nine years on, it is still considered quite a young cast. So did Broadbent have any reservations about working with such a vast number of hormonal teenagers?
"I've worked with younger, they didn't seem young, they're quite grown up now and quite sophisticated and very good young actors," he explains.
"I took it from them, as they inhabit their roles in such a natural and easy way that it's just good to be able to join them and try and get on with it as easy as they are. It's terrific."
Broadbent has won a number of acting accolades throughout his career, taking on varied characters from the put-upon dad in Bridget Jones to the dramatic role of political campaigner Lord Longford.
He has also worked on a number of gritty films with director Mike Leigh - including Life is Sweet and Vera Drake - where the cast arrive on set without ever having a script to work to.
Broadbent won a best supporting actor Oscar for Iris in 2002
In contrast, the Potter films are lavish productions which rely heavily on CGI to create grand scenes such as quidditch matches and strange beasts.
Broadbent says: "It wasn't a great deal of my stuff that was CGI-heavy. I don't find it that difficult, certainly what I had to do wasn't difficult.
"I find it interesting really. If I had to do a whole film which was CGI that would drive you round the bend.
"The amount I have done, I've just found it intriguing how they can do it, and the wonderful revelation when you see what has been done."
Broadbent has managed to straddle his career between credible indie films and blockbusters such as Indiana Jones and the Kingdom of the Crystal Skull.
The actor is already filming for the final two films based on the concluding book The Deathly Hallows, with a turn guaranteed to win over a new legion of young fans to his very British charm.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.