The River Ran Backwards

What it teaches

In 1900 Chicago reversed the flow of the Chicago River to keep sewage out of its drinking water — protecting the Lake Michigan supply you just fixed in 1.1.

How it works

Free-form AI dialogue. The engineer NPC accepts any answer that shows real understanding.

You’ll need first

• Water Main Key

Rewards

• Reversal Map
• 70 Onions
• +350 to the city supply gauge