The true story of the devastating 2015 Mariana dam disaster

Dead River investigates the cause and effects of the Brazil catastrophe. Plus: five of the funniest podcasts that also teach you something

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Who is behind the most notorious “deepfake” app on the internet? Trying to answer that question these past few months, for a new Guardian podcast series, Black Box, has been like wandering through a hall of mirrors.
The app, ClothOff, has hundreds of thousands of followers and has already been used in a least two cases to generate dozens of images of underage girls – pictures that have left the girls traumatised, their parents outraged and the police baffled at how to stop it.
Producers Josh Kelly, Alex Atack and I have followed ClothOff’s trail to nondescript addresses in central London that appear to be unoccupied. We have encountered sham businesses, distorted voices and photographs of fake employees.
It has been a frightening insight into the future we are all careering towards: in the age of artificial intelligence, is anything we see or hear on a screen real?
The hunt for ClothOff is just one of the stories we are telling about the time we are living through: the first years when AI is beginning to infiltrate our lives, but not yet so deeply that we can no longer remember life before.
We wanted to take a snapshot of this moment, to examine the impact AI is already having on the world and look for clues about what’s in store. We’ve met the scientist who pioneered AI software, before dramatically turning against it last year. We’ve listened to people reminisce about their first dates with their boyfriend (a chatbot on their smartphone) and heard of their heartbreak after a system update turns that same lover cold.
We’ve heard about the prospects of an AI system that can spot cancer years before doctors and machines that provide desperate people with something no person is giving them: humanity.
Everywhere we went, we ran into an even bigger mystery: the people using AI. Time and again, what has captivated us is not just the technology, but the way it is already reshaping what it means to be human in a series about artificial intelligence that’s really a series about us.

Michael Safi
Presenter, Today in Focus

Picks of the week

Hear Me Out
Widely available, episodes weekly
This chatty theatre podcast from actor Lucy Eaton gives you a snippet of multiple stars’ dramatic talent. They each pick a favourite speech, then act it out, amid a personal chat that gives it a feel of Desert Island Discs for the stage. The first episode of the latest series hears Mark Gatiss perform Hamlet’s “yearning” and “angry” “speak the speech” soliloquy, as used in Jack Thorne’s The Motive and the Cue. Alexi Duggins

Dead River
Widely available, episodes weekly
This troubling tale looks at one of the most devastating environmental catastrophes in history: the 2015 Mariana dam disaster in Brazil – which has led to the UK’s biggest ever class action lawsuit, involving 700,000 claimants. It’s an emotive, worrying listen packed with heartstring-tugging music, as we hear locals recount their fears that “the dam was sick”. AD

Blame It on the Fame: Milli Vanilli
Widely available, episodes weekly
You might already know the story of Rob Pilatus and Fab Morvan, but Insecure’s Amanda Seales brings us the backstory in this entertaining podcast. When German producer Frank Farian asked the tight-trousered pop duo to make a deal with the devil, it led to exploitation and tragedy when they were unmasked as fakes. Hannah Verdier

Time Capsule: The Silver Chain
Widely available, episodes weekly
The 1970s swinging scene is the stuff of myth and legend, so when Paul Ditty heard that secret club The Silver Chain had left a stash of newsletters in a safety deposit box he couldn’t resist an investigation. His brilliant unlocking of the mysterious Minnesota club starts with a simple question: how did they find time for all that partner swapping? HV

If I Speak
Widely available, episodes weekly
Novara Media journalists Ash Sarkar (above) and Moya Lothian-McLean swap politics for the personal (sort of) by tackling questions on their minds, such as “can you ever really be friends with your boss?”, “are dating apps dead?” and “should I give my mum an allowance?”. As Sarkar says, it’s “the place we can be our most unhinged and nosy selves without judgment”. Hollie Richardson

There’s a podcast for that

This week, Robyn Vinter chooses five of the best comedy podcasts where you actually learn something, from Chase star Paul Sinha’s comedic quiz to an investigation into the urban legends of black culture
Do Go On
It’s surprising this Australian podcast isn’t better known, given its longevity. Hosted by incredibly likable Melbourne comedians Matt Stewart, Jess Perkins and Dave Warneke, each week one of them chooses a topic to report back on – recent episodes have included the history of monopoly, the pirate queen of Ireland and Eurovision. Unlike a lot of other long-running podcasts (Do Go On is going into its ninth year), the inside jokes are easy to pick up and there’s a genuine and infectious enthusiasm from the trio. A rare podcast that is laugh-out-loud funny and full of fascinating tales.

Paul Sinha’s Perfect Pub Quiz
The Chase’s Paul Sinha is also a popular touring comedian, and he combines these pursuits in this whip-smart BBC Radio 4 podcast. Imagine an encyclopedia doing a tight 20-minute standup set and you’ll get somewhere close to this lively show. In series two, Sinha extends his trivia prowess to different parts of the country, testing residents of Ipswich about their most famous politicians and Manchester about their tallest buildings. There’s not much thinking time though, so listeners need to be quick with their answers.

My Momma Told Me
Comedians Langston Kerman and David Gborie take a deep dive into the world of black conspiracy theories, superstitions, urban legends and old wives tales told to them by, as they put it, “that uncle who used to wear jeans when he went swimming in the public pool”. The pair are frequently joined by hilarious guests, they discuss reader suggestions and, almost 300 episodes later, there is no sign of them running out of material.

The Big Flop
The newest of the lot with only a handful of episodes to date, The Big Flop is a show centred around things that went wrong, from the laughably awful movie Cats to the banned Four Loko, an alcoholic energy drink invented by frat boys. It is hosted by actor, singer and TikTok star Misha Brown, and made by pod giant Wondery. Two guests each week – mostly US standups and performers – bring freshness to each episode and it is well researched and nicely produced, thanks to an experienced behind-the-scenes team.

No Such Thing As a Fish
It would be difficult for anyone who likes comedy podcasts to have not come across No Such Thing As a Fish, made by the writers of the long-running BBC quizshow QI. The writers began the podcast in 2014, after finding funny facts during their research that never made it to air. Now a grandaddy of its genre with 500 episodes, the podcast is unapologetically nerdy but beautifully accessible for the non-Oxbridgers among us. Having won a number of well-deserved awards and spun out into books, No Such Thing As a Fish is a must-listen for those who like to be the one at the pub table with the quirky facts.

Why not try …

In the eight-part series Show on the Road, celebrities are taken out of the studio for a personalised road trip around the places that shaped them with presenter and seasoned podcaster Alex Legouix in the driver’s seat.

Just Jack & Will is the ultimate Will & Grace rewatch podcast with Sean Hayes and Eric McCormack.

Who’s the good guy? And who’s the bad guy? Alphabet Boys reveals the secret investigations of the FBI, DEA, ATF, and other three-letter agencies in the US.