"All fiction is about people, unless it's about rabbits pretending to be people. It's all essentially characters in action, which means characters moving through time and changes taking place, and that's what we call 'the plot'." - Margaret Atwood

I remember when I was a boy, admiring those Chris Foss covers on science fiction novels – amazing spaceships, fantastically scaled cities, gigantic robots – but I also remember thinking that the characters were very much secondary to the main event. They were tiny, if they were there at all. Nothing wrong with that. It was the scale Foss and other science fiction artists were going for. You only have to look at the opening shot of first Star Wars (episode IV) to see how impressive a hulking ship can be as it manoeuvres itself against a bewildering backdrop of stars, hanging over the great arc of a planet. But, as Margaret Atwood notes, it is the people that ultimately engage the reader or audience. 

Watch the excerpt from Christopher Nolan’s Interstellar, but beware, it’s emotional. This is at a turning point in the film – the ‘big event’, as it is called in screenplays, where the situation has been established and we now enter the second act and the main part of the story – and depicts Cooper and his daughter, Murph, as Cooper is about to set off in a rocket and enter a wormhole in an attempt to save the world:

Note down how the excerpt from Interstellar engaged you. The plot is a large and complex one and it has its basis in a reality the audience can relate to: crops are failing, there is another dustbowl, people need to find somewhere new to live. It is the basic plot of The Grapes of Wrath, but cast on a larger, interstellar stage. Nolan has taken on the post-apocalyptic subgenre and applied it to a world where ecological disaster is upon us. And he has added time travel into the mix, as well as a ghost story (the strange phenomenon in Murph’s room).

So, this has a convoluted plot idea. But is it this that keeps you watching in this scene? There are hard science elements here, but it is the relationship that has the biggest impact on the audience. Why? Is there a universal aspect at play here? Father/daughter? The trauma of separation? And how is the drama in the scene heightened? Murph and Cooper could just say a tearful goodbye. Would it have the same impact? And look at how much information is being released as Cooper and Murph talk and argue. The bigger picture is being built up – the idea of a great, dangerous quest, of other worlds and other time schemes – but this exposition is released dramatically. It isn’t just an ‘info dump’. If this information had been released with Cooper sitting at a table, explaining it to Murph, and her prompting him with questions, it would have been a static scene with dialogue that was driven by the plot rather than the characters. The dialogue would have been ‘stagey’/unconvincing.