skating on thin ice

Black ice, to be specific, which is actually not black at all but quite transparent. When the temperature hovers close to the freezing point, roads can acquire small-but-deadly patches of very thin ice. These tiny pockets of antigravity are virtually indistinguishable from the surrounding road surface — until you happen to drive over one, and discover that your brakes and steering no longer work. If it weren't for my cat-like reflexes, I'd be blogging to you from beyond the grave right now.