"Those red and green lights down the track," explained Freddie. "They blink so funny and come up and go out———"
"Just like winking at you," said Flossie. "I like it down here. It isn't like the dark tunnels we went in on the steam cars."
"Well, I'm glad somebody likes it," said Bert to Nan. "But say, how do we get out of here?"
"I'm sure I don't know," she said. "When I ran after Flossie I didn't look which way I was going."
"I didn't, either. Queer how we could get lost in a place like this," and Bert seemed worried and spoke more loudly than he intended. Freddie heard what his brother said and looked up quickly.
"Are we really lost?" he asked.
"It seems so," answered Nan. "I ran after you two, and we have walked about so many platforms and up and down so many stairs that I can't see or remember the place where Father told us to wait for him."
"Well, there's no danger, that's sure," said Bert. "It's a queer place to be lost in—a sub-
