Dog on Stairs

     Last night, around 8 pm, I went upstairs, by our rear staircase, to find a magazine I had been reading. The rear stairs end abruptly and turn to the right before continuing on up to the second floor. As I was ascending the stairs I very definitely saw the rear part of a grey dog make the turn in the stairs. As our dogs are not allowed upstairs except when we go up for the night; I thought our grey (salt and pepper) schnauzer had gotten through the gate somehow and was heading upstairs. I yelled his name, rather agitated I fear.  A bark from behind me alerted me to the fact that said dog was at the foot of the stairs, looking up at me with those big brown eyes that said "What did I do?" As our other schnauzer is black (actually a very very dark brown) it could not have been her. A bit embarrased, I had to go back down, remove the gate and allow the blameless dog to accompany me back upstairs. Needless to say there was no other dog up there. Had there been my little male would have known. He was just happy to be going where he doesn't normally. This isn't the first time I've seen dogs that weren't there. My wife has experienced the same several times so if I'm nuts were both nuts.