Classicly

Wyatt did not stop to think. He rushed up the stair after her and it began to draw itself up as he did so, folding him under, so that he thought he was going to have to jump clear or be crushed. There was a whine of power from inside. Damn her, thought Wyatt, she doesn't care if she kills me. He scrambled frantically up the tilting, flattening rungs and caught the edge of the aperture and kicked himself forward through it.