My girlfriend and i were at walmart, in germantown, wisconsin, she was inside shopping and i was in the car with our dog. i happened to look up and i saw this "box-like" thing in the sky. it flew out of the northeast to the northwest, as it moved along it changed shapes from being box like, to a more saucer like appearance. there was no wind to blow it along. at first i thought it could be some sort of big ballon that had sort of deflated, but it kept traveling to the northeast as though it was being intelligently piloted. it was strange because because it changed shapes from a dark box like object, to a more saucer shaped object. it was dull in appearance, and it seemed not to reflect light. it flew towards walmart out of the northeast as i first observed it, but then it kept precisely on the same course, i actually opened the car door to observe it, but it traveled pretty quickly over the walmart building, and i lost sight of it. it caught my eye, as i'm a kind of a fan of airplanes and i watch the skies frequently. but i've never seen anything like this.