“What’s funny?” asked Bert, wishing he could see something at which to laugh.

“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 subway station.  I was never in one before, but if we stay here long enough Dad is sure to find us.  Here comes somebody now, looking for us, I guess.”

A man in a blue suit, carrying a red lantern, and with white numbers on either side of his cap, walked toward the four twins.

“Is your name Bobbsey?” he asked.

“Yes; but how did you know?” was Bert’s question.

“Your father sent me to look for you.  He guessed you must have wandered away, and he thought it best to stay where he told you to wait, and let one of us find you.  A lot of men are hunting up and down the different platforms for you.”

“Well, I’m glad you found us!” sighed Nan.  “We didn’t know what to do.”

“Just come with me,” said the subway guard.  “I’ll take you to your father,” and he did, leading the children down a long platform and over a sort of bridge, then down a flight of steps.  Though they did not know it, the twins had wandered quite a distance from the place Mr. Bobbsey had left them.

The subway station was a rambling place, with several doors to go in by and come out of, a number of platforms and stairways, and wiser persons than four small children could easily become confused there.

When Mr. Bobbsey came back, after buying his magazine, and could not find his children, he guessed what had happened, and wisely asked a guard to make a search, instead of doing it himself.

“For I don’t come to New York often enough to be sure of finding my way around in all the odd nooks and corners,” said the lumber merchant.

“And it wasn’t a circus poster at all!” said Freddie, after Flossie had told what had caused her to wander away.  “It was only about chewing gum.”

Speaking of chewing gum made Flossie remember she was thirsty, and after Mr. Bobbsey had thanked the man with the red lantern, and had explained to Freddie that it was used to stop trains in case of an accident, the Bobbsey party went up out of the underground station and into a candy store.