Science fiction enthusiasts Hannah Black of Chicago (L), and Lucy French and her son Sol of London, all dressed as weeping angels from the television series Dr. Who, pose for a photograph outside the 12th annual Sci-Fi London festival in east London April 28, 2013. The international festival of science fiction and fantasy film runs from April 30-May 6. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY SCIENCE TECHNOLOGY) - RTXZ2UK