"This won't do," thought Billie. "He probably has some kind of a light, and if he gets on the landing and I'm up here, I'll be like a man up a tree."
The lad sat down and slowly slid toward the bottom.
Being only a few steps from the landing, Billie was down first. He crowded to the right and listened.
The other was now nearly on the landing. Now he was on the landing, hugging the wall on the side opposite Billie. Now they passed each other, or rather the man passed Billie, for Billie stood perfectly still.
It seemed as though he must hear Billie's breathing, but if he heard anything he must have thought it his own echo, never dreaming that he was not alone in the passage.
Now Billie could hear him ascending the stairs leading to Santiago's house, and his hope rose high.
"He must know how to open the floor," thought Billie. "I'll be right there when he does."
Silently as a cat Billie crept up the stairs behind his unknown companion.
Near the top the man stopped and a minute later he flashed an electric light against the stone overhead. Another minute and he heaved with the top of his head and the slab slid back.
"And now," exclaimed Billie in a deep voice, "put your hands over your head!"