A sketch a day: storm

Yelena Shabrova ~ A sketch a day: storm ~ pastel & charcoal, 6" x 4"
A sketch a day: storm ~ pastel & charcoal, 6″ x 4″

A somewhat failed experiment with charcoal on top of soft pastels – I was aiming for a little different, more dramatic look. Apparently a workable fixative is not capable of holding even a thin amount of pastel in place, and it keeps mixing with charcoal. I wonder what would work better?