A stranger in a dream rarely represents an actual unknown person -- more often it's a part of yourself you haven't recognized yet, or a quality you're growing into. Pay attention to how the stranger makes you feel: that reaction is usually the real message, more than anything they say or do.
The Superior Planets are most efficacious; the inferiour are weak, and easily do suffer by the Superiours, and receive good or ill from them. - William Lilly (1602.-1681.)