Tranquilly my pair look on, chewing crumpets, and tranquilly they retire to bed with their teddy bears. Disney and Harry Potter have trained them to watch extinction with a steady eye.
Last night, though, they were traumatised. Night lights had to be improvised and guardian angels invoked. But last night there were no cartoon bodies hurled from heights and no Lord of the Dark Arts felling foe. They had watched a fetching evacuee bond with a fetching old man in a glorious flintstone village in Buckinghamshire.
In one scene in Goodnight Mr Tom, the evacuee's mother had served him a tea of boiled eggs. I sometimes serve my children a tea of boiled eggs. She'd leaned up close and fondly and her son had presented her with a picture he'd painted her, just as my children often do for me. Only the gesture turned the mother into a monster and she raged and abused him and my children looked on, faces frozen in appalled incredulity.
They can cope with on-screen carnage secure in anticipation of a dose of Enid Blyton and a goodnight cuddle. But the notion of a treacherous mother is a horror too hard for them to handle.
I am gratified at this reminder of my significance and frightened by the weight of my responsibility. When I bawl out my babies for bedroom chaos or abandoned peas, and when I harry them to bed because I'm too tired to be kindly, I hear echoes of that irascible mother in me. I worry that one day, through exhaustion, or boredom or inattention I will let them down.
And so I have hidden Goodnight Mr Tom behind 12 espisodes of The Doris Day Show and I have dusted down an abandoned VHS tape of Snow White. I'm hopeful that that murderous, glamorous stepmother is so safely removed from the reality of me that she'll console my terrorised children and bolster my faith in my own mothering.