In the not-so distant future, researchers at a Underwater habitat have finally invented a time machine. The device can move objects ahead 24 hours, but the scientists have never tried it on people before. Head researcher Woo-seok is promised major funding from a mega-corporation if he completes a test run. Along with his assistant Young-eun, he schedules a jump to 11 a.m. the next day. Upon their successful arrival, they find the base in pandemonium, while the other researchers have disappeared. What's more, someone is out to get them. With the CCTV as the sole clue, they must investigate for the next 24 hours the mysterious happenings that occurred at the lab, figure out what happened over the past day and go back in time in order to prevent it.