Sometimes, you can see beyond the screen into where a film started out. And in Me and Orson Welles the inevitable conclusion is that this is an adaptation of something that existed first as a novel, and that proves to be the case: the book was written by Robert Kaplow and translated into a screenplay by Holly Gent Palmo and Vince Palmo Jr.

Is the film’s prosy background a problem? Not necessarily. But for my tastes it grounded the film into something cosier than it could have been, a safe piece of mainstream entertainment rather than something Welles himself would have concocted. OK, no fair pitching Richard Linklater against the man who brought us Citizen Kane on film, War of the Worlds on radio, and a definitive staging of Shakespeare’s Caesar. But you get the gist.

What’s served up is a coming of age story in which a precocious 17 year old played by Zac Efron comes to inhabit the orbit of the even more precocious Welles, superbly played by Christian McKay. Efron gets a role in the aforementioned Caesar production, and with it an initiation into a late 30s world of sex and booze and creative tantrums.

There’s not a lot you haven’t seen before in one form or another, but it’s done well enough that you can forgive the air of familiarity. Besides, I was sitting in one of the luxury £16 seats at the Belsize Park Everyman, and enjoying the novelty of coffee and carrot cake being brought out into the audience by staff.

Anyway, you won’t be surprised to hear that Welles comes across as a petulant genius, buttering people up one minute and casting them out later when he’s lined up a less mouthy replacement. And seeing that sequence run through once or twice should prepare you for what happens to Efron when he has the temerity to face off with Welles. As soon as Efron has done his opening night performance, Welles bins him. Ouch.

And that, you see, is the rite of passage element to all this. Naive young man is captivated by one of the world’s greatest conjurors, and surprised to land with a bump when he starts to see through the smoke and mirrors.

Fortunately there’s this girl to help him dust off his wounds, a wannabe writer we first meet in the film’s opening, and again at the end when she’s had a story accepted by The New Yorker. All of which was a bit too cutesy for me, the two scenes bookending the film rather too neatly and, well, bookishly.

I’d have liked a messier story. Maybe one in which Efron’s character demonstrates some of the cunning he’s learned in the company of Welles, and uses it to advance his cause back in the world he returns to. Something at any rate in which everything isn’t resolved so neatly and in such a story writing 101 manner.

Still, there is plenty to like about Me and Orson Welles. It looks pretty good, the performances are strong across the board, and it can’t help but make you smile at times. Part of your response to it will depend on how you react to stories of theatre folk, and I’ve known too many for real to be easily charmed.

Let’s be generous though. It’s December, and if you’re looking for a feelgood film to take the family to over the Christmas period, this is a good option, a modest success that can be enjoyed by all ages. And it’s another curious installment in the career of director Richard Linklater, whose films have gone on a trajectory from indie favourite Slacker to mainstream comedy success School of Rock via less easily defined semi-animated projects Waking Life and A Scanner Darkly.