As ghouls swished gently over my head, it was as if the floor was shaking.
No, wait, that was the floor shaking.
At first I wasn't sure if 3D movie technology had advanced even further than I thought. But it turns out that Tim Burton's The Nightmare Before Christmas wasn't supposed to be that scary.
The crowd at San Francisco's Sony Metreon mall took the 30 seconds of rolling in stride, but there were all sorts of whispered queries as to whether that was the movie or an earthquake.
And when the lights came on after the film ended an hour and fifteen minutes later, it was all anyone could talk about.
Of course, it did turn out to be an earthquake. Not that anyone was too upset with having some extra thrills.
"It was pretty good timing as far as earthquakes go," said the person walking out of the theater ahead of us. "I thought someone was kicking my seat," said their companion.
My partner, AJ, said it was like a 3D roller coaster. "It's definitely the most fun place to experience an earthquake."