Gabriel Weston continues to look at extreme medical cases that could hold the key to future cures.

We meet Steve Ludwin, who has been injecting himself with snake venom, believing it to have healing properties. Wim Hof can survive two hours immersed in ice, while Jordy Cernik feels no fear.

Gabriel goes to Denmark to meet scientists working with Steve on the first human antivenom for snake bites (horse antivenom is often used but can have side effects), discovers how Wim’s unique breathing techniques are putting him in control of his immune system, and how Jordy’s adrenaline deficiency could lead to a cure for anxiety.

We also meet a woman who functions with half her brain, and the first man to be cured of HIV.