Hannah embarks on a journey to investigate her own biological age and whether it can really be controlled; on the island of Okinawa in Japan, she sees the key to some of the healthiest old women in the world.

Cars that can sense anger; laptops that know if the user is bored; Hannah explores how emotional recognition technology is creeping into users' lives and the consequences.

Hannah meets with writer Patrick Tomlinson who is targeted by KiwiFarms, an online hate group that used his data to dox him and his wife; Hannah explores how AI can be used to write reams of text and potentially convince people of false views.

It's the holy grail for limitless clean energy, but nuclear fusion might not come soon enough to avoid the worst of the climate crisis; in France, Hannah Fry goes inside the largest international fusion project ever built.

Hannah travels to Japan to visit a robot café run by disabled staff from their homes; she explores new prosthetics technology, making use of machine learning; she debates whether AI will really be a magic bullet for social inclusion in the future.

The environment is in crisis, but a revolutionary new conservation concept offers hope for the future; from the overgrown Fukushima exclusion zone, to the majestic redwood forests of California, Hannah embarks on a journey into the wilderness.