Salva Rubio is a Spanish author and a screenwriter who has worked in movies, television, and animation. He was a finalist for the prestigious Premio SGAE de Guión Julio Alejandro Screenwriting Award, and the short film Checkout, which he wrote and codirected, was preselected for the 2010 Goya Awards. Cristina Pérez Navarro is a Spanish artist and an illustrator who has worked in publicity, public relations, and with a number of publishing houses. She is the author of two wordless books for children: En el silencio and El último día de verano.