Valerian and the City of a Thousand Planets is based on a French sci-fi comic book series written in the '60s and has boatloads of potential. The adaptation from comic to screen materializes as a futuristic world where Valerian (Dane DeHaan) and Laureline (Cara Delevingne) are federal agents who are assigned a mission on Alpha, a space station that became a mega-city where many species have gathered to share knowledge and to live. The supporting cast include big names such as Rihanna, Ethan Hawke, Clive Owen, and John Goodman.  Before I chug along with my review of Valerian, I need to let out a long, disappointed sigh.