Then the doors snap shut, and I am rising, quickly, skyward. As I watch a sweeping panorama of snowy mountains expand before me, I feel the wind whipping at my face, hear the winches grinding in my ears, and feel the floor swaying and shaking beneath my feet.

The elevator jerks to a halt at the top of the Wall; I step out and walk across hard-packed snow. I can’t stop. I feel pulled, moving inexorably toward the edge until I stand at the precipice, 700 feet up with nothing but open air in front of me. I panic, yell, and pull away–and suddenly there is a hand at my back.

It’s an HBO rep, trying to keep me from falling out of the booth in which I am testing the Oculus Rift experience “Ascend the Wall.” The demo, part of a Game of Thrones exhibition here at SXSW that includes costumes and props, allows fans to strap on an Oculus Rift VR headset, don headphones and venture into Westeros for a brief but utterly immersive experience.