The Shadow was listening for any sound of approaching police cars.
The Shadow listened a few minutes; then moved to the rear door of the study, opened it and entered.
The Shadow tilted his head and listened, then laughed again.
The Shadow listened at the door of the hidden laboratory.
The Shadow was listening to words that came from the house next door.
The Shadow listened to the even beat of her heart and realized that the girl was merely unconscious.
The Shadow listened, not a muscle moving in his gaunt face.
The Shadow listened to the change in tune; then gave a whispered laugh.
The Shadow listened; thought that he heard sounds from within.
The Shadow listened, but there was only the single voice talking as if to itself.