*contains spoilers*

The moment in The Truman Show when Jim Carrey’s boat bumps up against a soundstage and he realises that he’s in a TV set. When Michael Douglas touches a price tag hanging from a lampshade in his girlfriend’s apartment in The Game and realises everything is fake. Arnold Schwarzenegger noticing a drop of sweat on the forehead of one of the baddies in Total Recall and realising this is not a dream…

Every film fan has his own favourite genre — obviously mine is the thriller — and a subset of which could be the chase thriller (North By Northwest, The Fugitive), the conspiracy thriller (Three Days of the Condor, The Parallax View) or the heist thriller (The Killing, Ocean’s 11). There’s something in each subgenre that speaks powerfully to each person on an individual basis.

My personal favourite is what I call the “discombobulation” story — i.e. what on earth is going on? — or less politely, the mind**** movie. Films that mess with your head. Great examples include the Spanish film Open Your Eyes (later remade as Vanilla Sky); Martin Scorsese’s Shutter Island, based on the Dennis Lehane novel; and the original Total Recall, where an average Joe construction worker is told that in reality he is a James Bond character who lives on Mars (Richard Dreyfuss and William Hurt were among the original choices for the role, not Arnold Schwarzenegger, whose cartoonish-ness makes you think he could be capable of anything anyway).

Often the reveal of these films — and here I am going to put my Madame Pretentious turban on — are a metaphor for the nature of reality. And what is reality keeps changing. So, in The Matrix the reveal is that we are all trapped in a computer simulation, while The Truman Show has the metaphor as being reality television (seems dated already, right). Drugs were the reality in the Sixties, which is why psychedelics are the reveal in Jacob’s Ladder.

This kind of story seems less common in literature, although The Magus by John Fowles is one good example. The reveal there is an unhappy mix of existential roleplay and Classical Greek mythology. Total Recall (great title) was based on Philip K Dick’s awkwardly-named Do Androids Dream of Electric Sheep?

However my personal favourite has to be David Fincher’s The Game because game-playing is such a timeless metaphor: Michael Douglas finds himself trapped in a self-help cult that turns into a murderous game.

So, what is a good metaphor for reality today? Big data harvesting everything it can about you or the American intelligence agencies hoovering up metadata about every website you visit is the metaphor of the moment. However, as a thriller writer, I am scratching my head trying to think of exciting scenes involving Excel spreadsheets and data-mining. Any of you think of something better?