This was the terrifying moment a wildlife cameraman stared into the jaws of a hungry 70-stone polar bear in the middle of the frozen Arctic.
Film-maker Gordon Buchanan had only a perspex safety box to stop the 8ft predator killing him with a swat of her giant paws and feeding him to her cubs.
The 40-year-old described the 45-minute confrontation as the most frightening of his 20-year career, as the powerful beast probed for a weak spot in his protective cage.
"A lot of people think that carnivores are intrinsically dangerous but most aren't - there's a minimal risk and attacks are the exception. But polar bears are different," said Buchanan, who was filming the bears for a three-part BBC documentary.
"Without a doubt she wanted me for lunch. She was so persistent, looking for a weak spot for almost 45 minutes.
"I was terrified and you could hear my heartbeat on the mic. It really was a sensational moment and a worrying situation."
Buchanan spent 12 months tracking mother Lyra and her two cubs, Miki and Luca, on Svalbard, a tiny archipelago 400 miles off the coast of Norway.
He risked long journeys over and through the ice, often into uncharted territory, battling freezing winds, violent storms and deep subzero temperatures.
His film crew had to take to their snowmobiles several times to flee the polar bears.
Although the perspex 'ice cube' was built to be "pretty much bombproof", there was a risk it would become brittle in extreme cold - a risk that was tested to the limit when Buchanan came face to face with Lyra.
He said: "It is the most difficult thing I have done and the scariest. I've not been terrified for 40 minutes before.
"There's no doubt polar bear cubs are the cutest animals in the world and even the adults have an aesthetic which isn't threatening.
"But the polar bear is the animal I have the most respect for, it is the largest and strongest land carnivore. They are such inquisitive animals too.
"The landscape is pretty featureless and it is amazing how they appear from nowhere."
The Polar Bear Family and Me is broadcast on BBC2 on Monday, January 7 for three consecutive nights at 9.30pm.