“Just what I expected,” he muttered. “But I guess I can get it open. There’s only a wooden button on the other side. I might break the door right through, but it would make too much noise. My knife will fix it.”

One of the blades of his jackknife was long and thin. He thrust this between the door and the jamb, and pushed the button out of the way.

“Ridiculously easy!” he said to himself. Then, to Patsy: “We have to get at the outer doors, you know—the one into the kitchen regions, as well as the other on the main floor. The worst of it is that they are on the other side of the house. We’ll have to make our way there. Or, rather, I shall.”

“What about me?” asked Patsy.

“Stay where you are, in the dark. It will be better to have you ready in case I need help, than to let you get into the muss with me. Don’t you see that?”

“I s’pose you’re right,” grumbled Patsy. “But I don’t like this waitin’ game. Maybe I won’t get into it at all. Things are always breakin’ wrong for me. Just when I’m all primed up for a rough-house, I’m put on guard duty, like a boy at a henroost. Holy Perkins! It’s tough!”

Chick did not stop to argue with his companion. It was clear that if Nick Carter and three or four policemen were to get into the house, they could not take the time to dribble through the opening in the cellar wall by which Chick and Patsy had made their way from one cellar to the other.

When they came up the steps from the cellar, they were on the basement floor, level with the bottom of the courtyard in front of the house, and below what was known as the parlor floor, with its main hall leading to the principal door to the street, at the top of the stone steps outside.

Passing along the stone-floored hallway, after making sure that Patsy was out of sight at the door by which they had come up from the cellar, Chick found a door closed, but under which could be seen a line of dusky red light.

He realized that he was coming near to the heart of the mystery he and Nick had set out to solve.