Everything you need to understand or teach The Ones Who Walk Away from Omelas by Ursula K. Le Guin.
The people of Omelas live in a city of peace and prosperity. They celebrate life and have everything necessary to make them happy. However, the foundation of the city is built on the misery of a single child. One child is chosen from the population to serve as a sacrifice that will allow the rest of the city to live in peace and plenty. The child is placed in a small, windowless room without any amenities and is completely cut off from the rest of society except for the short visits from those who come to view The child.