S1, E3: Our planet is at a crossroads. A changing environment and shifting population patterns present significant new demands on cities worldwide. Luckily, people are coming up with ingenious answers. In Bangladesh, old school meets new as communities rise above floodwaters. Modular bikes in South Africa and vertical gyms in Venezuela allow end users to fit their needs (and even have fun along the way). And two groups in Africa are planting seeds. The first, in Kenya, is working towards food security in slums. And in South Africa, it's the seeds of cultural understanding that have been planted at a vibrant community crossroads.