The Thunderbolt Kids are planning a camping trip but have no clean drinking water at their campsite. They ask the student's class to help design and build a water filter to purify water from a nearby stream for the large group. The document provides guidance on researching water filters, designing a filter using recyclable materials, building and testing the filter, then evaluating and communicating the results. The goal is for the students to work together to build a functional water filter that can clean muddy stream water for the camping trip.