Q: Passage: The story of Daniel in the lions' den (chapter 6 in the Book of Daniel) tells how Daniel is raised to high office by his royal master Darius the Mede, but jealous rivals trick Darius into issuing a decree which condemns Daniel to death. Hoping for Daniel's deliverance, but unable to save him, the king has him cast into the pit of lions. At daybreak he hurries back, asking if God had saved his friend. Daniel replies that God had sent an angel to close the jaws of the lions, "because I was found blameless before him." The king has those who had conspired against Daniel, and their wives and children, thrown to the lions in his place, and commands to all the people of the whole world to "tremble and fear before the God of Daniel".

Question: Based on this passage, who was put in the lion's den? Let's give stream of consciousness first:
The relevant information is: Hoping for Daniel's deliverance, but unable to save him, the king has him cast into the pit of lions. Therefore, the final answer is Daniel.