In the 16th century, witches and demons weren’t just for Halloween. People were terrified and preoccupied with them – even kings.

In 1590, James VI of Scotland – who was later also crowned James I of England – travelled by sea to Denmark to wed a Danish princess, Anne. On the return journey, the fleet was hit by a terrible storm and one of the ships was lost.

James, a pious Protestant who would go on to sponsor the translation of the King James bible, was convinced he’d been the target of witchcraft. A few years later, James decide to write a treatise called Daemonologie, setting out his views on the relationship between witches and their master, the devil.

Meanwhile, another firm Halloween favourite – ghosts – had fallen out of favour in the wake of the Protestant Reformation because they were seen as a hangover from Catholicism.

In this episode, Penelope Geng, an associate professor of English at Macalester College in the US who teaches a class on demonology, takes us back to a time when beliefs around witches, ghosts and demons were closely tied to religious politics. She explains how these beliefs have come to influence the way witches and ghouls have been portrayed in popular culture ever since.

This episode was produced by Mend Mariwany and Katie Flood with mixing by Eleanor Brezzi. Theme music by Neeta Sarl. Gemma Ware is the executive producer. Read the full credits for this episode and sign up here for a free daily newsletter from The Conversation.

If you like the show, please consider donating to The Conversation, an independent, not-for-profit news organisation.

• From printing presses to Facebook feeds: What yesterday’s witch hunts have in common with today’s misinformation crisis
• Samhain: the true, non-American origins of Halloween
• What’s the difference between ghosts and demons? Books, folklore and history reflect society’s supernatural beliefs

One American company called Strategy owns more than 3% of all bitcoin in existence. In August 2020, its executive chairman, Michael Saylor, pioneered a new business model where publicly listed companies buy cryptocurrency assets to hold on their balance sheet.

More than 100 other public companies have since followed Saylor’s lead and become bitcoin treasury companies, together holding more than $114 billion of bitcoin. There’s been a new rush into crypto treasury assets in 2025 following the general crypto enthusiasm of the new Trump administration.

But holding bitcoin assets also comes with some big risks, particularly given the volatility of cryptocurrency prices, and the share prices of some of these companies are now coming under pressure.

In this episode, we speak to Larisa Yarovaya, director of the centre for digital finance at the University of Southampton in the UK, about whether bitcoin treasury companies are the future of corporate finance, or another speculative bubble waiting to burst.

This episode was produced by Mend Mariwany and Gemma Ware with assistance from Katie Flood. Mixing by Michelle Macklem and theme music by Neeta Sarl. Read the full credits for this episode and sign up here for a free daily newsletter from The Conversation.

If you like the show, please consider donating to The Conversation, an independent, not-for-profit news organisation.

• Cryptocurrency’s transparency is a mirage: New research shows a small group of insiders influence its value
• Bitcoin: why a wave of huge companies like Tesla rushing to invest could derail the stock market
• Could digital currencies end banking as we know it? The future of money

As one of the birthplaces of the industrial revolution, the River Mersey in northern England is no stranger to pollution flowing into its waters. Now it's got a new problem: monitoring shows the amount of forever chemicals, also known as PFAS, entering the Mersey catchment area is among some of the highest in the world.

In this episode we speak to water scientist Patrick Byrne at Liverpool John Moores University in the UK about why so many per- and polyfluoroalkyl substances (PFAS), are still making it into our rivers, many from sources that are lying hidden. Identifying these sources of pollution, can help prioritise how to clean them up.

This episode was produced by Mend Mariwany, Katie Flood and Gemma Ware. Sound design and mixing by Michelle Macklem and theme music by Neeta Sarl. Read the full credits for this episode and sign up here for a free daily newsletter from The Conversation.

If you like the show, please consider donating to The Conversation, an independent, not-for-profit news organisation.

• You can be exposed to PFAS through food, water, even swimming in lakes – new maps show how risk from ‘forever chemicals’ varies
• Australia has banned 3 ‘forever chemicals’ – but Europe wants to ban all 14,000 as a precaution
• How I tracked the biggest hidden sources of forever chemical pollution in UK rivers – new study