“I remember watching TV as a kid, and whenever there was some sort of jeopardy in…” — Jed Mercurio

Some shows do nosedive at the end, or some piece of content could become incredibly controversial and affect the way the show is seen.

I think it's hugely important to have a strong episode one; you can lose an audience so quickly now. You can't afford to take the attitude that you will use the first one as an introduction and save the high drama for later.

I've never reached the point where I was ready to abandon a series.

There's a classic medical aphorism: 'Listen to the patient; they're telling you the diagnosis.' Actually, a lot of patients are just telling you a lot of rubbish, and you have to stop them and ask the pertinent questions. But, yes, in both drama and medicine, isolated facts can accumulate to create the narrative.