When the Chernobyl nuclear power plant exploded 33 years ago in Soviet Ukraine, it was the largest ever accidental release of radioactivity into the environment. The cause, and who was to blame, is still being debated. But what's become of the people who refused to leave the exclusion zone, and the wildlife left behind? Just how contaminated is the area now? The BBC's Science correspondent, Victoria Gill, has been given rare permission to go inside the zone - and the plant itself.

For centuries, a significant Sikh minority has grown in relative safety in Afghanistan. But, in the last decade, persecution has seen the population drop.

In northern Europe's Lapland, temperatures are rising faster than anywhere else in the world, threatening the livelihood of its indigenous Sami people. Central to Sami life is the ancient practice of reindeer herding, but climate change is putting the reindeer at risk of starvation. Many Sami also worry that plans to build a railway, to exploit Lapland's natural resources, will add to the pressure on their traditional way of life. For Our World, Erika Benke has been to Arctic Finland to hear from Sami women about their fears for the future.

Google, Apple and Facebook-owned Instagram are enabling an illegal online slave market by approving and providing apps used for selling domestic workers in the Gulf. For Our World, BBC News Arabic’s undercover investigation exposes the people in Kuwait breaking local and international laws on modern slavery, including a woman offering a child for sale. At the centre of this powerful investigative film is Fatou a 16 year old in Kuwait City who has been there for nine months. We follow her rescue and journey back home to Guinea, West Africa and ask what’s being done to control these apps?

For five months protests have rocked Hong Kong, pitting hundreds of thousands of young, idealistic demonstrators against the authorities and the might of China. The clashes between police and protestors have become increasingly violent and neither side shows signs of backing down. Our World goes beyond the frontline to tell the stories of some of those involved, what drives them - and their hopes and fears for the future.