Let's analyze the valence intensity of the snippet "Who are 'they'? Well, they're 'they'. They're the unnamed, easily substitutable forces that serve as whatever terror the heroes of horror movies try to avoid. They exist for hushed lines like ''They're back!'', ''They're out there!'' and ''They're coming!''". Assign a real number between 0 and 1, where 0 indicates extremely negative and 1 indicates extremely positive.