Calm in the Canopy.

A wealthy middle-aged man at the airport witnesses a tiny incident involving an unknown, perhaps Arab, young man and airport staff. After the young man is confronted directly at the airport toilets, he feels himself subject to an indefinable but increasingly serious sense of danger. The fear of the evil that had, as it were, encircled the man since then, gradually becomes an obsession. The urgent desire to see the evil, to confront it and destroy it.