Contagious The Contagious Smile. One day, Emma went to school with a big smile on her face. Her smile was so bright that it became contagious. First, her friend Sarah saw Emma’s smile and started smiling too. Then, Sarah’s smile was contagious and spread to their classmates. Soon, the whole class was smiling. Even the teacher noticed the contagious smiles and couldn’t help but smile as well. By the end of the day, the entire school was filled with contagious happiness, all because of Emma’s smile.