January 27 - April 13, 2020*

*Please note: Our spring 2020 Mystery Class challenge is a replay of a previous year's challenge. You have open access to all of the season’s clues (Weeks 1-11). We will reveal the locations of the 10 Mystery sites on April 13, 2020.

Mystery Class is a global game of hide-and-seek. Students track seasonal changes in sunlight and then investigate other clues to find ten secret sites around the world.