Due to sudden deteriorating weather conditions, visibility on the Airport Bridge is severely impaired, leaving people stranded and at risk of the bridge collapsing due to a series of chain collisions and explosions. Amidst the chaos, the canine subjects "Echo" from the military experiment "Project...
Dong-hyun is a high school student. One day, he falls from the rooftop and bumps into Pan-soo who is a passerby. Pan-soo is a member of a criminal organization. When the two men wake up in the hospital, they discover that they have switched bodies.
Jung-yoon was approached by a random stranger named Jun-woo, who told her she'd be dead in six hours. As she follows him for answers, she begins to question whether he's her savior or the one trying to put her in danger.
