It was a dark and stormy night. A secret message arrived addressed to Rutherford & Fry from a mysterious woman called Heidi Daugh, who demanded to know: "Why do people like to be scared? For example, going on scary amusement park rides and watching horror movies that make you jump.”

What followed was an investigation, which would test our intrepid duo to their very limits. They explore the history of horror, starting with its literary origins in the Gothic fiction classic 'The Castle of Otranto'.

Adam challenges Hannah to watch a horror film without hiding behind a cushion. She quizzes horror scholar Mathias Clasen to find out why some people love the feeling of terror, whilst it leaves other cold.

Sociologist Margee Kerr and psychologist Claudia Hammond are also on hand to explore why scary movies are so powerful and popular.

Never ones to shy away from a challenge, the pair attempt to channel their inner adrenaline junkies with a trip on one the UK's scariest roller coasters at Thorpe Park.

David Poeppel from New York University studies the science of screaming, and we discover what makes screams uniquely terrifying. Plus, psychologist and broadcaster Claudia Hammond describes some early experiments which tested how fear affects our body.

This episode is a remake of two earlier broadcast episodes.

Producers: Fiona Roberts & Michelle Martin

Presenter: Adam Rutherford & Hannah Fry

First broadcast on BBC Radio 4 in February 2021.