From The Grey House:
A door slammed at the other end of the hall. Natalia looked at Charlie then vaulted onto the cage using a gymnastics trick. She lightly touched the bars with her hands, managing to only scratch her palms. She landed on the top bars in a crouched position, grateful now for the spikes, which gripped her rubber-soled canvas sneakers. She stood, turned around, braced her feet on two bars shoulder width apart, and crouched down. Natalia grabbed the bars Charlie indicated and pulled up. Nothing happened. She could hear Lucas. He was almost to the door. No longer caring about the spikes she repositioned her feet, leaned forward, grabbed the bars and pulled hard.
Cat Stark 