From the Old Testament reading at Evening Prayer:

When the king heard the charge, he was very much distressed. He was determined to save Daniel, and until the sun went down he made every effort to rescue him. Then the conspirators came to the king and said to him, ‘Know, O king, that it is a law of the Medes and Persians that no interdict or ordinance that the king establishes can be changed.’
Then the king gave the command, and Daniel was brought and thrown into the den of lions. The king said to Daniel, ‘May your God, whom you faithfully serve, deliver you!’ A stone was brought and laid on the mouth of the den, and the king sealed it with his own signet and with the signet of his lords, so that nothing might be changed concerning Daniel. Then the king went to his palace and spent the night fasting; no food was brought to him, and sleep fled from him.
Then, at break of day, the king got up and hurried to the den of lions. When he came near the den where Daniel was, he cried out anxiously to Daniel, ‘O Daniel, servant of the living God, has your God whom you faithfully serve been able to deliver you from the lions?’ Daniel then said to the king, ‘O king, live for ever! My God sent his angel and shut the lions’ mouths so that they would not hurt me, because I was found blameless before him; and also before you, O king, I have done no wrong.’ Then the king was exceedingly glad and commanded that Daniel be taken up out of the den. So Daniel was taken up out of the den, and no kind of harm was found on him, because he had trusted in his God.
(Daniel, chapter 6, verses 14-23, NRSV)

A parable of how good people get manipulated into doing bad things.

This glass is a section of the east window in Michaelhouse, Cambridge.