Chris Hemsworth is best known as the hammer-wielding Norse god Thor in Marvel's cinematic universe.
But now the Australian actor is trading superpowers for science, introspection and a new set of personal challenges, many of which are far scarier than battling fictional villains.
The 41-year-old is back for a second season of Limitless which sees him confront some of his deepest fears as he explores how to live longer, healthier and better.
"The first season almost killed me," Hemsworth tells the BBC. "And I thought, 'never again.'"
In season one, Hemsworth tackled physical and mental challenges designed to delay aging including free diving, fasting, stress training and walking along a crane 900 feet above the ground.
