He turned to the girl. “Beth, who was at the door just now?”
“Two men.” She trembled slightly. “They carried knives, so I opened the door on the outside. They—they hurried away.”
“I dare say!” The professor chuckled dryly.
“Press the button, Beth,” the professor said, nodding his head toward the right wall. “Our guest will stay for cocoa and cakes, I am sure. That right?” he asked, turning to Johnny.
“I will, yes,” Johnny agreed.
The girl pressed a button like a lamp switch in the wall.
The boy’s feelings were mixed. He wanted to stay. These people interested him and there were a hundred mysteries to solve,—living skeletons, eyes blinking from the walls, self-opening doors, lights that gleamed and clocks that buzzed.
A fresh mystery was added when five minutes later the girl pressed a second button and a tray laden with cups, saucers, a plate of cakes and a pot of steaming cocoa appeared.
“The ‘Eye’ did it for us,” the professor explained in a matter-of-fact tone. “In these days one scarcely needs a servant even when he is able to afford one.”
Perhaps Johnny would have said, “What is the ‘Eye’?” but at that moment the door at the rear opened and a tall youth with tumbled red hair appeared.