On a time of autumn he came in the dusk of evening, and drawing near [Gorlim] saw as he thought a li

On a time of autumn he came in the dusk of evening, and drawing near [Gorlim] saw as he thought a light at the window; and coming warily he looked within. There he saw Eilinel, and her face was worn with grief and hunger, and it seemed to him that he heard her voice lamenting that he had forsaken her. But even as he cried aloud the light was blown out in the wind; wolves howled, and on his shoulders he felt suddenly the heavy hands of Sauron’s hunters. Thus Gorlim was ensnared; and taking him to their camp they tormented him, seeking to learn the hidings of Barahir and all his ways. But nothing would Gorlim tell. Then they promised him that he should be released and restored to Eilinel, if he would yield; and being at last worn with pain, and yearning for his wife, he faltered. Then straightaway they brought him into the dreadful presence of Sauron; and Sauron said: ‘I hear now that thou wouldst barter with me. What is thy price?’

And Gorlim answered that he should find Eilinel again, and with her be set free; for he thought that Eilinel also had been made captive.

Then Sauron smiled, saying: 'That is a small price for so great a treachery. So shall it surely be. Say on!’

Now Gorlim would have drawn back, but daunted by the eyes of Sauron he told at last all that he would know. Then Sauron laughed; and he mocked Gorlim, and revealed to him that he had seen only a phantom devised by wizardry to entrap him; for Eilinel was dead. 'Nonetheless I will grant thy prayer,’ said Sauron; 'and thou shalt go to Eilinel and be set free of my service.’ Then he put him cruelly to death.

–J.R.R. Tolkien, The Silmarillion, “Of Beren and Lúthien”