The paint and brush were in the kitchen and as I left the stairs I disturbed the covers but thought it would be OK to redo them once I had the paint. BIG MISTAKE!
Coming back with paint and brush I stumbled on the damned covers and when trying to stop myself from falling I spilt the paint. It could have gone anywhere, but no, it zoomed in with pinpoint accuracy to the uncovered part of the carpet!

Thank goodness I have insurance.