I can only assume this was military activity, not sure if it was a tech demo of some sort or they were chasing an object. it began approximately at 940pm with four(4) standard appearance planes, almost could have looked commercial, except they were very obviously in a linear formation, circling the area above riverside wa in okanogan county, circling, beyond my viewing perimeter, approximately two or three times. i chalked it up to personnel carriers moving hr out of fairchild afb (spokane county) to another site so i went to bed around 10pm. around 1050pm i heard droning, continuously for about 15 minutes and went outside to check it out. there was another plane (only one), looking exactly and sounding exactly like one of the earlier personnel carriers (im saying personnel carriers because it was just a normal feeling aircraft, nothing special, although from the indicator lights it appeared oddly triangular. i can only assume it was a standard usaf design) seeming to follow another.. object. the object appeared very similar in design to the others, only it did not have standard indicators at all, not even a blink, let alone the one red blink of the others, and it was either much smaller than the plane, or much, much higher in elevation. im not sure if its some kind of tech demo, like how we can get arduino quad copters to follow each other with short range wireless only with larger aircraft, or what the hell is going on, the plane doesnt appear hostile to the object, whatever it is. it's 1150pm and this plane is still following the object around in circles above my house. the plane is making standard engine noise, but i have no idea what the other thing is. i honestly dont know what to make of this situation. should i call fairchild?