In Act Three of The Crucible, Gile Corey interrupts the court proceedings to assert that the court has been "hearing lies" and that Thomas Putnam has been "reaching out for land." Corey's wife has been accused of witchcraft and to save her, he puts forth evidence that the girls "afflicted" by witchcraft have been deceiving everyone: a document with an anonymous statement that accuses Mr. Putnam of prompting his daughter to pretend to be affected by witchcraft. Putnam knew that if those accused of witchcraft were found guilty and executed by hanging, they would be forced to forfeit their property; only Putnam had enough capital to make large land purchases in Salem.

Thus, Corey claims to have the statement of an "honest man" who heard Putnam admit this himself. Corey cannot reveal his source because he knows that this "honest man" would be thrown in jail and accused himself if his name were revealed to the public. Unfortunately, without the verification of this person's identity, the courts refuse to accept his testimony. 

He says he was told by an honest man about an overheard conversation wherein Thomas Putnam was heard to say that he told his daughter Ruth to cry witch against Mr. Jacobs, his neighbor in order to obtain his land.

Giles refuses to reveal is source because he knows that to do this will probably end up with that honest person being brought to the court and possibly accused of witchcraft as well. By now, Giles and the others who are trying to stop the court from proceeding have seen enough to know that no one is safe from an accusation of witchcraft, and he is not willing to endanger his source in this way.

Giles Corey accuses Thomas Putnam of reaching out for land because Ruth Putnam accuses George Jacobs of witchcraft.  Mr. Jacobs is the Putnams' neighbor, who owns 600 acres next to their property.

After Martha Corey is arrested, Giles Corey storms into the court, hoping to prove that the girls are lying, pretending to see spirits.  He gets resistance from the court, and Thomas Putnam.

He says that he has information about the case against George Jacobs, that he knows for a fact that Thomas Putnam has instructed his daughter to accuse Jacobs of witchcraft.  In fact, Giles Corey tells Danforth that he has it on good authority, from a reliable source, who overheard Putnam instruct Ruth to accuse Jacobs.

However, when Danforth demands that Giles name the source, the man who overheard Thomas Putnam instruct his daughter to accuse George Jacobs, he refuses to name him.  He refuses to give the man's name, and is hauled off to jail, and later executed by being pressed to death.