Best known for his novels of suspense, Ken Follett returns to medieval England in World Without End, a sequel of sorts to 1989’s Pillars of the Earth, his most successful book.

Does Pillars of the Earth have any similarities to your thrillers?

Pillars is like my thrillers in that it’s a story of intrigue, adventure and romance. A thriller is like a snapshot: you see the characters frozen at one stage in their lives, during a single terrible crisis. In Pillars you are with the characters as they love and hate and struggle from childhood to old age.

Why the long gap between Pillars and World Without End?

At the end of Pillars all the principals are very old or dead, so I couldn’t write another book about the same people. I settled on a story that takes place in Kingsbridge 200 years later. I also felt the need of a theme as powerful and all-embracing as the building of a great cathedral, and eventually I thought of the Black Death, a disease that killed at least one third of the population of Europe in the 14th century.

And yet the first passage dealing with the Black Death doesn’t appear until more than 500 pages into the story.

I wanted all the main characters to have thoroughly realized lives, with ambitions and love affairs and a history of friendships and enmities, so that when the Black Death finally appears, it turns everything upside-down. When you know these characters, you feel much more moved by the catastrophe of the plague than if it had happened nearer the start of the book.

Despite its epic proportions, World Without End focuses on a relatively few important characters.

Everything is seen through the eyes of five characters who know each other intimately from childhood, and I think this makes the story easy to follow even though it’s long and complex.

What differences are there for you in writing a suspense novel or a historical novel?

Longer novels require a much richer range of dramatic themes. World Without End was the first time I made an Excel spreadsheet of the characters. The program calculated their ages at each stage of the novel, so that I didn’t make mistakes. I found the spreadsheet a big help and I plan to do it for all future books.

Do you have another epic in mind?

I have a couple of ideas, but I’m not ready to talk about them yet—sorry!