Mike and Irina Conboy are a couple of tie-dye clad scientists in the bio-engineering department at the University of Berkeley. When they started researching ageing more than 20 years ago at Stanford, the field was nothing more than a spin-off from geroscience - most of their time at the lab bench was spent documenting signs and signals that our bodies are reaching their ends.

But in 2005, they published an article in Science that suggested there is hope for reversing ageing our tired old bodies. And the best bit of their study was that they proved there’s ample supply of the base material to do it - young blood. Using a revolutionary but ancient technique, their results re-ignited the millennia-old search for life everlasting.

In this series, technology reporter and psychologist Aleks Krotoski explores the frontiers of the extreme longevity pioneers. They've made their money in Silicon Valley. And with their technology solutions - PayPal, Facebook, cryptocurrencies - they've ushered in the world that we live in today, with all its unintended consequences. Some of them now want to solve the "problem" of aging, or even death, and they are making bigger strides than we may think.

Can they? Should they?

A Pillowfort production for BBC Radio 4

New episodes released Mondays. If you're in the UK, listen to the full series of Intrigue: The Immortals first on BBC Sounds: bbc.in/3WEQS5W