He climbed into the niche, which was no bigger than the bunk of a steamer, and began to examine his surroundings with his torch. Inspector Armadale, taking advantage of the space thus made clear, crept into the tiny chamber.
“This place looks as if it had been washed out, lately,” he said, examining the smooth flagstones which formed the floor. He turned his attention to the roof, evidently in search of dripping water; but he could find none, though the walls were moist.
Suddenly Sir Clinton bent forward and brought his lamp near something on the side of the niche.
The Inspector, seeing something in the patch of light, craned forward to look also, and as he did so he seemed to recognize what he saw.
“Why, that’s . . .” he ejaculated.
Sir Clinton’s lamp went out abruptly, and Inspector Armadale felt his arm gripped warningly in the darkness.
“Sorry,” the Chief Constable apologized. “My finger must have shifted the switch on the torch. Out of the way, Inspector, please. There’s nothing more to be seen here.”
Inspector Armadale wriggled back into the passage again as Sir Clinton made a movement as though to come out of his perch in the recess.
“So this is where Maurice got to when he left the museum?” the Chief Constable said, reflectively. “Well, he isn’t here now, that’s plain. We’ll need to look elsewhere, Inspector, according to your scheme. If he wasn’t elsewhere he was to be here. But as he isn’t here he’s obviously elsewhere. And now I think we’ll make our way up to the museum again. Wait a moment! We’ve got to get back into that passage with our heads in the right direction. Once we’re into the tunnel there won’t be room to turn round.”
It took some manœuvring to arrange this, for the tiny chamber was a tight fit for even three men; but at last they succeeded in getting back into the tunnel in a position which permitted them to creep forwards instead of backwards. They finally accomplished the long journey without incident, and emerged through the gaping panel into the museum once more.