Silently the panel swung open, revealing a niche in the wall, but nothing else.

A panel swung open, disclosing the mouth of a black tunnel.

He twisted each of them in turn- A panel beside the fireplace swung open without a sound.

A panel whose existence he had never guessed swung open in the floor beside him.

Slowly the panel swung toward her, revealing a dark aperture in the wall behind.

She reached out a hand: there was a click, and a small panel in the side of the cabinet swung open.

The panel swung back, giving him a clear view of what lay beyond.

A panel in the door swung open, and he tumbled through.

Slowly a panel in the far wall swung wide open and a spectral figure stepped into the room.

At that moment, the white panel swung all the way open and Joshua strode inside.