PICK OF THE WEEK

Free Solo National Geographic, 7.30pm Sunday (Also available on SKY Go and SKY OnDemand)

One of the cameramen says it best. He’s been filming Alex Honnold, the rock climber at the centre of Academy Award winning documentary Free Solo, as he prepares for his biggest and some may say stupidest climb yet. At one point he just shrugs and goes: “There’s a lot of things I don’t totally understand about him.”

The film has a go at helping us understand. The best explanation is probably the bit where Alex has a brain scan, and it turns out he might just be missing a part of his brain, the part that tells most people: “Hey man, maybe don’t try to climb one of the world’s tallest cliff faces without any ropes.”

El Capitan in Yosemite National Park is some 900m tall, a sight so striking it’s the default desktop background on a lot of Apple computers. Alex has already climbed it dozens of times with ropes, but now he wants to be the first to do it “free solo”.

“There’s no margin for error,” explains Alex’s climbing buddy Tommy Caldwell. “Imagine an Olympic gold medal achievement where if you don’t get the gold medal you’re going to die.”

If I imagined that any longer than four seconds it would give me stress nightmares for weeks.

Alex doesn’t die, obviously, but knowing that doesn’t make it any less terrifying to watch. A sense of dread builds over the course of the documentary that makes it feel a bit like you’re watching a horror movie. You see the growing unease in the faces of the camera crew, his friends, family and new girlfriend(!) — everyone but Alex.

The climb itself is one of those unforgettable scenes, both excruciatingly stressful and breathtakingly beautiful at the same time. And the sense of relief you feel when it’s over — it’s worth watching just for that.