I believe a Babysitting movie with Christina Applegate had my very bright 5 year old first born son think he could tie Mommy up to a chair. We only saw that movie once. The gleam in his eye was very interesting and scary.
This was one of my favorite movies as a child. Since it came out when I was 11 it seemed as if it could all actually happen.
I'm watching it now as a 33 year old mother of five and its AMAZING the different take my mind takes. Ironically, I am happy to have seen it as a young child and adult to see how much my views have changed.
Hopefully this can help explain the "glimmer" in your sons eyes :)