Israel is conquered and some top young men are forced into the service of the Babylonian king. Taken from their culture, it’s about what stays and what is ephemeral.
They undertake three years training to be servants of the king. Daniel considers the kings food and wine a defilement, and indeed it’s probably not kosher, or ancient equivalent.
So he and his mates drink only water and eat only vegetables. They flourish and come top of the class, skills that mix learning with a fair bit of mysticism and magic. God grants them insight to know dreams.
The great meta salvation plan of God appears to have gone backwards. Yet here he is still active in Daniels life. Where will this book run with it?