As James mentioned his state of undress, Emma realised that she too wasn't wearing any clothes. It took only a quick scan of the room to reveal the stack of clothes, which she hastily threw on.
"Okay," she began, "There's a heavy metal slab on top of your coffin-thing."
At once she wished she hadn't said that. While she had somehow managed to get out, it was a genuine possibility that she wouldn't be able to get the others out, and anyway, she didn't quite trust herself not to run - trying to think everything through was a struggle through the rising sense of panic when her fight-or-flight mechanism told her only to escape.
"Why don't you try pushing upwards, and I'll try to lift?" she suggested, "Together we might be able to-"
Hearing the voices from outside, Emma froze.
"Damn... everyone, be quiet," she hissed.
She was wrong about the urge to run, she realised. It wasn't the urge for flight. It was the urge to fight.
Lifting the broken wood from the chair, she snuck over to the door, and raised it into the air. Anyone who came in would have it slam down upon their head. Further than that, she'd just have to wing it...