Sitting upstairs at my computer before breakfast doing emails (I know, how sad), I was startled by Dave the Windows appearing silently, fuzzy window-wiper in hand, blocking out the light. Now after about 17 years of working round here, Dave is used to seeing me and probably many other customers in their dressing gowns and bed hair, but usually you hear the ladder being put up at the window and you can compose your features a little to look less like you've been dragged through a hedge backwards.
Today he had stepped silently across from the front door ledge, fooling even the dog, who fancies herself as ever-alert, especially, fearsomely, fang-flashingly alert to men in baseball caps.
Dave just said "It's the Ninja Window Cleaner!" and carried on.
Dog, you have much to learn.