Thomas Craven is a man of impulse and no consequence. Your daughter being shot to death would do that to you. Especially if she was standing beside you on the front porch. So begins Mel Gibson’s first acting appearance since 2002, as a father seeking revenge (or answers) for his daughter’s death. As the second adaptation of a BBC series this summer (following January’s In The Loop), Edge Of Darkness holds a mix of British and American filmmaking, but the merger fails to deliver.