Here on Unexpected Elements, we've been glued to the drama of the Paralympic games in Paris. But it's not just the thrill of the competition that's got us hooked, we've also become obsessed with some of the high-octane training regimes undertaken by the athletes.

Take American 'Armless Archer' Matt Stutzman, who shoots arrows through the windows of his own house and car to recreate the high pressure of the Olympic stadium. He's chasing a thrill, and so are we!

We hear about the research on one extraordinary woman who had a medical condition which caused her to have no fear.

And we follow the fate of an extraordinary marine creature, who detaches his own arm in his quest for a mate.

We hear about why humans love to be scared - as long as it's all in good fun.

And we hear about the space debris falling to earth, and the thrilling quest of a plane full of scientists who want to watch it fall.

That and loads more unexpected elements in this week's show.

Presenter: Marnie Chesterton, with Tristan Ahtone and Affelia Wibisono Producer: Emily Knight, with Harrison Lewis, Dan Welsh and Noa Dowling Sound engineer: Gwynfor Jones

Following anti-tourism protests across popular Spanish cities and towns, we are looking for the world's most unwelcome visitor. Our panellists (and producers) are pitching their terrible tourists to see who really is the worst of them all. Some of our contenders include...

The wild boars who's unanticipated vacay to Rome has gone on for so long and caused so much carnage that researchers are putting them on birth control.

The microbes potentially hitching a ride to the moon via space probes and astronauts' poo

The multi-destination parasite who wreaks havoc as it interrails through snails (castrating them on the way), frogs (making them spout multiple limbs) and birds.

But there are some instances when tourists can be a good thing - and this is especially the case in the human body when we want to grow a baby. How is in that we are able to protect what should be an 'unwelcome visitor' from a hyperalert, hostile immune system? Our expert Edward Chuong explains.

Plus, we uncover the DNA origins of the world's most popular coffee bean, hear the freeloading activities of the male angular fish, and read out a selection of your wonderful emails.

Presenter: Caroline Steel Panellists: Phillys Mwatee & Christine Yohannes Producer: Julia Ravey Production team: Emily Knight, Noa Dowling Studio manager: Emma Harth

The US astronauts Butch Wilmore and Suni Williams are currently stranded on the ISS. They arrived on the Boeing Starliner, which was meant to bring them home after eight days. Unfortunately, it has run into tech issues, meaning that the astronauts may be stuck up there for up to eight months.

We started to ponder, what could an extended period of being stuck in space do to your body?

Next we look to the world of psychedelics research, which has currently got itself a little bit stuck.

We also find out more about the Haraldskær Woman, discovered preserved in a Danish bog in the 1800s. Mads Ravn, head of archaeology, research and collections at the Vejle Museums in Denmark, reveals the stories behind the bog bodies and explains how they ended up stuck in the mud.

And staying with the theme of stickiness, we find out what Neanderthals used as glue.

That, plus many more Unexpected Elements.

Presenter: Marnie Chesterton, with Camilla Mota and Kai Kupferschmidt Producer: Harrison Lewis, with Alice Lipscombe-Southwell and Noa Dowling. Sound engineer: Mike Mallen

The Olympics is all about flying the flag for your home country, shoulder to shoulder with your team-mates. But what if you have no team-mates? At this year’s Olympic games, four countries had just one competitor. Like Sean Gill from Belize, Somalian runner Ali Idow Hassan, or Romano Püntener, a mountain-biker representing Liechtenstein.

This got us thinking about the only one. The panel discuss what it must be like to be an ‘Endling’ – the last remaining animal of an otherwise extinct species, and wonder if there might be ways to bring them back.

We delve into the intriguing psychology behind the urge to collect things, why collectors are so entranced by rare items, and how the psychological pull of ‘exclusivity’ and ‘limited editions’ can make us vulnerable to marketing scams.

And what about a baby, born of only one parent? A ‘virgin birth’ – a miracle perhaps? Not so, as we discover that females giving birth without any help from males is surprisingly common. It is called Parthenogenesis, and although humans cannot do it, a dizzying array of animals can. Alexis Sperling from the University of Cambridge explains the science.

News montage sources: Channel 5 Belize, BBC News

Presenter: Marnie Chesterton with Chhavi Sachdev and Andrada Fiscutean Producer: Emily Knight with Florian Bohr, Julia Ravey Sound engineer: Emily Preston