He softly retreated.

Keeping his eyes fixed on the huge, sleeping leopard, Timokles put out his hand to take hold of the door through which he had come.

His groping fingers found nothing but the blank wall! Hastily turning with alarm, Timokles passed his hand over the wall's surface.

Surely the door had been here! There was no handle, no line in the wall to indicate the existence of a door.
How silently it had swung shut, when he had come through! He remembered that there had been no noise.

He pressed his full force now against the wall.