From the introduction: "Why is Venus so much hotter than the Earth? You are a group of experts gathered from around the world to solve this long-standing mystery..." This is a collaborative problem-solving exercise about the greenhouse effect on Venus. Students role-play biologists, coal geologists, space warfare experts, astronomers, pollution-control scientists, and hydrophysicists. Each student gets a copy of the appropriate briefing sheet (there are 6) containing some information important to solving the problem, much of it quantitative.