Adapted by writer/director Mark Herman from the source novel by John Boyne, this is a majestic portrait of evil that boasts all the intimacy of a theatre piece. It touches on mass murder on an industrial scale but manages to convey all of its horror and terror via the emotional responses of an eight-year-old boy.

It's the Second World War, and Bruno's father is given a promotion that takes him from their spacious home in Berlin to a grey, ascetic house close to a farm worked by ragged people dressed in striped pyjamas.

Naturally Bruno (Asa Butterfield) explores his new domain and, venturing close to the farm, the chimneys of which belch out noxious smoke, he meets Shmuel, a Jewish boy, behind the barbed wire fence. The two become friends.

At home his 12-year-old sister is slowly indoctrinated by a tutor to espouse (and repeat) the credo of National Socialism. Jews, she parrots, are "evil, dangerous vermin". It's an awful testament to how a mind can be warped in the space of four short years.

Her mother, on the other hand, quietly rebels against the regime. So does Bruno, though he doesn't know it. But his friendship with Shmuel (Jack Scanlon) will take him on a journey to tragedy and a terrible truth.

The Boy in the Striped Pyjamas is a tremendous extension of a brilliant story that winds its way to a devastating coda that leaves audiences in stunned disbelief. Unlike some previous dramas in this narrow genre it never labours its message, nor does it brandish a banner of sentimentality or go in for finger-wagging admonishment. Instead, there is a slow journey towards recognition and understanding – an appreciation of how intolerance can slowly mutate and become something far more malevolent.