Well, I was reading just outside my house and I happened to look up and a small flash of light(like you get when sunlight reflects of metal) caught my eye. Just slightly above the treetops (at a distance) was a silvery shape. At first I thought this was just an airplane, but it couldn't be, since it was motionless(and silent). I squinted to get a better look, since the object was reflecting the late-afternoon sun, and I saw that it was a disc, no wings, no tail. At that moment, a chill ran through me and I suddenly became very afraid, and that someone or something was watching me, but I held my ground. Such thoughts as, "Oh my God!" and "Oh crap!" ran through my head as I observed this object. The thing made a few slow manuevers and stopped again, just hanging in the sky. Then, seemingly out of nowhere, another object showed up. This one was a black triangle with an outline similar to the stealth fighter. At first I thought it was just that, a stealth fighter, but it made no noise. The triangle headed quickly towards the disc and it looked like it was going to crash into it, but the disc took evasive action. The triangle proceeded to chase the disc about the sky, as if it was trying to chase the disc off and then the two objects shot across quickly to the west and vanished from view.I stood there for a few moments, dumbfounded, before shakily picking up my book, and heading inside. I felt like a great weight had been put upon my shoulders and I was scared, really scared (I didn't get a wink of sleep that night either). I had two more sightings apiece of the two objects over a period of four months, each showing up at an interval of two months.