Watch HDToday. Cheng Yu, the lonely sojourner in the bustling city, goes in and out of a different empty house every day, prying into the city's secrets. He doesn't know why he's here, nor does he know where he'll go tomorrow. By chance, he saw the eighteenth-string actress Hu Mengya in an online drama, but never imagined that in the next seventeen days he would experience the three most important points in his life.