Q. I show a female cop near the beginning of my script, but she doesn't speak.

As I start Act II, I introduce an old women, who is really the cop, in makeup prosthetics to look like an old woman.

Do I tell the reader that the cop and the old woman are one and the same? Or do I let the reader know when everyone else finds out?

A friend of mine says “the director and the crew need to know right away.”

A. They will, but you’re not writing a shooting script. You’re writing a selling script. A selling script should read the way you want the audience to experience the movie.

Later on, should your script go into production, you’ll make everything clear; but in a selling script, secrets should remain secrets until they’re revealed.

You can, if you want, write something like “We’ll see her again,” to let us know to pay attention to this particular cop; it’s the equivalent of the camera dwelling on this particular cop for just long enough that we know we should remember her later.

Actually, why doesn't she speak? What's the point of introducing her at all if we're not going to notice her?

Another question: is she the main character? If so, maybe we should know she's in disguise. If the main character knows critical things we don't know, it alienates us from him or her. You can do it, but we won't identify with him or her as much.