I have a series of static shots 10 or so, with a subject passing thru the frame. The camera does not move but the subject does. How can I make a panoramic photo of this? The usual way does not work.

I have a series of static shots 10 or so, with a subject passing thru the frame. The camera does not move but the subject does. How can I make a panoramic photo of this? The photo-merge does not work properly.