Historian Catherine Merridale witnessed the birth of Memorial in 1989 as the Soviet Union died. An organisation devoted to recovering the past of the Soviet Gulag and soon documenting the new transgressions of the Russian state and its imperial wars. Even as Russia wnet to war against Ukraine it sought to close Memorial down, silence its voice and reshape history. But months after the invasion Memorial shared in the Nobel Peace Prize, only adding to the Russian government's ire. It has closed its archives and offices and pursued leading figures in Russian Memorial through the courts, declaring them responsible for 'rehabilitating Nazism'.

Merridale tells a personal story of the opening of history that Memorial was essential to and the tragedy of its closing and the closing of the past. The Kremlin's current occupants are no more willing to consider the victims of state repression - largely Stalin's repression - than their Soviet predecessors were. The story of Memorial, the association, established in 1989, that set out to find, investigate and discuss the Soviet Union's record of political violence against its own citizens, is one of real heroism. From its initial aim of creating a physical memorial to Stalin's victims it became a focus for research and advocacy, a living witness to the intellectual freedom that comes after the past is faced.

The state argues that what it does - harping on about Stalin's crimes - dilutes great Russian patriotism. Some of its critics have gone as far as to say that Memorial's work helps to justify Nazism. But branches of Memorial in Ukraine and elsewhere in Europe do what they can to keep memory alive.

Producer: Mark Burman

In 1997 a freak wave washed 62 containers into the sea off a cargo ship near the coast of Cornwall. Inside one were five million pieces of Lego. By a strange quirk of fate, many of the Lego pieces had a sea theme. This is the story of the community of beachcombers trying to track down the miniature octopuses, scuba tanks, life rafts, flippers, sharks and some very rare green dragons still washing ashore today.

Beachcomber Tracey Williams set up the social media account Lego Lost At Sea, allowing people to share their finds. She leads BBC reporter Robin Markwell on a journey around the Cornish coastline looking for the tiny toys.

On the way they meet fishermen still bringing up Lego in their nets, families brought together by dragon-hunting and an artist making sculptures out of millions of pieces of microplastic. Lego Overboard is a tale about the joys of treasure-hunting with a serious message about the long-lasting legacy of plastic pollution in our seas.

Producer: Robin Markwell for BBC Audio in Bristol

Two decades ago Da Vinci Code mania gripped the world. But the story behind the theory that Jesus Christ had a secret bloodline is more surprising than any thriller. Step aside Indiana Jones and Robert Langdon - BBC Paris Correspondent Hugh Schofield heads to the South of France to uncover a forgotten milestone of broadcasting which helped set the template for the modern conspiracy theory.

The Lost Treasure of Jerusalem was a 1972 episode of the BBC history series Chronicle. It sets out the unusual local mystery of Rennes-le-Château - and the charismatic parish priest who somehow funded a major church renovation. What treasure had he uncovered? Written by and featuring the actor-turned writer Henry Lincoln, the programme was a phenomenon.

The idea that the church was decorated with symbols and clues hinting at the origin of the unexplained wealth gripped viewers and led to two follow-up programmes. But Lincoln's research for the programmes became the keystone of the book The Holy Blood and the Holy Grail - popularising theories of Christ's marriage which went stratospheric with the 2003 release of The Da Vinci Code. Intrepid Hugh reveals the forgotten global impact of the Chronicle series - speaking to The Damned drummer Rat Scabies who had a surprising ringside seat for much of the drama, and to Dame Marina Warner who was the star of a thrilling encounter with the three authors whose book was about to become a global best-seller.

We hear how this forgotten series popularised a spurious new approach to historical research and facts - one that reverberates through conspiracy theories today.

Presented by Hugh Schofield

When a gang of youths attacked and killed an Antiguan man in 1959, it sparked uproar in the local community, in the press, and even drew the attention of politicians. Like Stephen Lawrence, Kelso Cochrane was a black man stabbed to death by a white gang on a London street.

His death brought the local community together, black and white - it helped lead to laws against discrimination, and the annual Carnival in the streets of Notting Hill. But no-one was ever prosecuted for the murder, and questions linger about the approach of the Metropolitan Police. Their investigation files have been sent to the National Archives but are closed for another 30 years. As Sanchia Berg discovers, Kelso Cochrane’s family are embarking on legal action to try to get them open.

Producer: Charlotte McDonald

Dr Kat Arney explores cancer through the lens of evolution.

Why do we get cancer? In this episode we find out that far from being a new disease, cancer is embedded deep in almost every branch of the tree of life, from the very earliest organisms through to today, and in most species from aardwolves to zebras. Kat explores how the origins of cancer are inseparable from the history of life itself, with the help of some ancient mummies, cheating amoebas, lazy bees and naked mole rats.

Produced for BBC Audio Bristol by Beth Sagar-Fenton

Emily Knight lives with five housemates. One of them is her partner. But this isn't a student house-share. They are all in their 30s, have no plans to break up the group, and Emily can't imagine life without them all. So could the rest of her life be built on these friendships?

Producers: Paul Martin & Emily Knight

Anxiety is the most common form of mental illness in the UK, with nearly a fifth of people experiencing it over the course of a year. Although it is often treated through medication, there are many alternative ways which are proving to be very effective in reducing anxiety amongst some people. In this series, we explore how connecting with the elemental forces of nature helps people with a range of mental illnesses to feel better. We also learn about the current academic research behind these methods.

In Episode 1 - Fire - we visit an overnight camp on the banks of the River Spey near Aviemore in the Scottish Highlands run by the charity Fire and Peace. According to the participants, - who have a range of mental ill health and addiction issues - the experience of spending time around the fire in nature is transformative when it comes to promoting feelings of connection and wellbeing. We also hear new research which shows how being around a campfire can be calming.

Produced and Presented by Helen Needham

A BBC Scotland Production made in Aberdeen for BBC Radio 4

Sheep have been instrumental in creating some of the UK’s most iconic upland landscapes – from the sweeping fells of the Lake District, to the moors of Devon and Cornwall.

These humble animals have left their mark on our language, our place names and even our architecture. But upland sheep are under fire. As the farm subsidy system changes post Brexit, it’s getting harder to make money out of them. The wool is now less than profitable, and lamb consumption has decreased. Meanwhile, sheep are being criticised by many environmentalists, who say they have degraded upland habitats.

In this programme, Charlotte Smith travels from Dartmoor to North Wales, exploring the places and meeting the people who have been formed by sheep…and asking what their future holds. What is the trouble with sheep? Answers range from being picky eaters, to getting bad press!

Produced for BBC Audio in Bristol by Heather Simons

As a deadly new virus starts spreading in Wuhan, China, so do rumours about a lab there.

In the remote, jungle-covered hills of China’s far-southwestern Yunnan Province, teams of scientists have spent years intensively researching one animal: bats. The scientists are virus hunters, trying to better understand and mitigate the threat of new viruses jumping from bats to other animals and humans, potentially setting off a pandemic.

Their samples of bat droppings are brought back to labs, including the Wuhan Institute of Virology. So when a new coronavirus begins killing people in that same city, questions are raised about whether the people trying to stop a pandemic could’ve accidentally triggered one.

Archive: CBS; The White House; NPR; CGTN; NBC.

Presenter: John Sudworth

Tales of a bipedal ape-like creature persist in the myth and legend of the Himalayas. But does the yeti really exist? Two enthusiasts are determined to find out. Andrew Benfield and Richard Horsey begin their search in the north-east Indian state of Arunachal Pradesh.

Speaking to villagers and yak herders, they hear multiple accounts of yeti sightings. Will they find the evidence they need to prove the creature is real?

Producer: Joanna Jolly.

A Loftus Media production for BBC Radio 4