He stands in the open, removes his glasses (his shield), and yells at the killer using Shinichi’s raw, unfiltered rage. He doesn’t care about the secret anymore. Let the world burn. Ran is about to die.
It is the thesis statement of the entire series. And no film explores this more beautifully, more painfully, than Movie 4: Captured in Her Eyes ( Meitantei Conan: Hitomi no Naka no Ansatsusha ).
She knows. We, the audience, know she knows. But she says nothing.