Studious environmentalist Charlie is stuck with a science fair partner who seems like her complete opposite: Charlie wants to save the planet, and all Oliver wants is to doodle in his notebook. But when a mechanical mishap sends the two traveling back through time, they'll have to work as a team to return to the present day. In order for the time machine to send them back, the unlikely duo must gather data on recycling throughout the ages-from sustainable marketplaces in Edo Japan to garbage-gobbling pigs in 19th-century NYC. Yet the closer the team gets to the present day, the more that plastic presents a problem: they're running out of time. Harnessing their frustration over the daunting ecological future they've inherited, Charlie and Oliver discover the ways in which they can use their sustainability knowledge to return home and build a better earth.