Here's a short story:

CHAPTER X 

NAT POOLE WANTS TO KNOW 

That evening Dave was on his way to the school library, to consult a certain work of reference, when he ran into another student who suddenly grasped him by the shoulder. It was rather dark where the pair confronted each other, and for the instant our hero did not recognize the fellow. 

"What do you want?" 

"I want to speak to you for a minute, Dave Porter," said the other, in a voice that trembled a trifle. 

"Oh, it's you, Nat," answered Dave, as he recognized the son of the Crumville money-lender. "What do you want?" He rather imagined that the youth wished to pick another quarrel with him. 

"I--I want to talk in private with you," returned Nat, and looked around, to see if anybody else was near. 

"What about?" 

"You were out walking this afternoon and met that wild man, so I heard." 

"That is true." 

"You tried to catch him, didn't you?" 

"Yes, Roger Morr, Buster Beggs, Gus Plum, and I did our best to collar him, but he was too fast for us. He ran down to the river, got into a rowboat, and rowed away." 

"So I heard. And I heard something else," continued the boy from Crumville. "When you called to the man to stop he answered back, didn't he?" 

"Yes." 

"Will you please tell me what he said?" And Nat's voice had an eager ring in it. 

"He told us to beware and go back, or we'd get into trouble."  (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: What is the name off the chapter?
Guess: CHAPTER X

Question: What time of day is it?
Guess: Evening

Question: Where is Dave headed?
Guess: The school library

Now answer the following question in the same format.

Question: To do what?

To consult a certain work of reference